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"The Itchy Brain Simulation" is the eighth episode of the seventh season of the American sitcom The Big Bang Theory. The episode first aired on Thursday, November 14, 2013.


Leonard tries to keep Sheldon from overreacting when a past mistake comes to light, but Sheldon punishes Leonard by making him walk a mile in his shoes by wearing an itchy sweater. Penny meets and confronts Raj's ex-girlfriend, Lucy.

Extended Plot

Penny asking questions about the dart board

While in Leonard's apartment, Penny asks why she has never seen them using the dart board on the back of their front door. Leonard reveals that the only time they used it, he broke a window with a dart, ninety degrees to the right and twenty feet away. Sheldon enters and asks where the skeeball tickets are. After three years, Sheldon has decided which prize he wants at the arcade. Leonard sounds skeptical; however, he feels they might be in the junk box. Sheldon unfortunately implies he wants a squirting lapel flower. Leonard finds the tickets and a sweater his aunt made for college that is bright

Please don't freak out.

red, itchy and has "Lenny" written on the front. Penny wonders if his aunt despised him. Leonard sarcastically disagrees since he got the sweater and his brother got a car. Sheldon is short some tickets and wants Leonard to look again in the box. Leonard barely looks and then tells Sheldon that he can look if he promises to not flip out. Sheldon gasps when he asks if there is a spider in the box. Penny quips that it's not a spider because if it was "Lenny" would have flipped out. Leonard pulls out a DVD that they rented on his card and should have returned a long time ago (seven years). He begs for Sheldon to remain calm which Sheldon does so and asks him to return it. Sheldon agrees and that freaks out both Leonard and Penny because Sheldon is being surprisingly reasonable.

Leonard starts to discuss with Sheldon, what it means to not freak out about the DVD. Don't fixate on it, don't wake him up in the middle of the night, don't nag him while he's on the toilet. Talking to Leonard while he is on the toilet is not a picnic for Sheldon either. They can hear each other. Also, he completely disregards how uncomfortable unresolved issues are to Sheldon. He describes it as an itch in his brain that he can't scratch. Leonard had a similar experience when he had a cast on his arm and had to stick a coat hanger down to scratch his itches. Leonard suggests that he stick a coat hanger in his ear. Sheldon replies that he wouldn't make jokes if he could feel the way he does. Then he agrees to not pester him about the DVD if he will wear the sweater until the matter is resolved with nothing underneath it. Leonard thinks it's stupid and doesn't understand why. Leonard has said that the sweater is itchy and uncomfortable; Sheldon feels the same way about unresolved issues. Sheldon wants them to share the experience and Leonard mistakenly agrees. Leonard tells him that if the sweater makes him shut up, he'll make a fortune selling them to everyone he knows. He puts on the sweater and heads down to return the DVD. Then Sheldon claims that the video store went out of business years ago as the sweater starts to bother Leonard so he scratches. Sheldon wonders how Leonard's nipples are feeling.

Waving to Lucy.

Amy and Bernadette are at the bar and Penny has not yet delivered their drinks. Amy and Bernadette both described their scientific work they did earlier in the day, while Penny added that she scrapped gum from underneath a table; granted it was her gum. Amy notices Lucy, Raj's former friend at another table. Penny always pictured her as Indian. Bernadette describes her comment as racist. Penny wants to go over to talk to Lucy because she hurt her Indian friend. Penny then asks who is racist now. Bernadette added that she just called Raj her Indian friend. Penny calls her short and leaves. Penny asks if she can get her anything to drink and Lucy asks for water. Then she identifies herself as Penny, Raj's friend who was identified by Amy and Bernadette. They wave while reaching for the beers they never received. She asks how Raj is and tells her that he is good. Then she asks why she broke up with him by an email. Lucy tells her she guesses that it was easier. Of course it was easier for her, not for him. Lucy asks for a different waitress, seeming to have improved since last season. Penny continues that she can sit there while Raj is at home a blubbering mess. Lucy remarks that she thought she had said he was fine. Penny quipped that she also said she was going to get her water and she is still standing there. Penny tells her that she may be a bad waitress; however, she is a bad person. Then Penny asks a shocked Lucy if she wants to hear what the specials are.

Leonard's bear imitation.

Sheldon, Howard and Raj and having dinner together in Apartment 4A while Leonard fidgets in his itchy sweater. Howard asks if he can ever take the sweater off. Leonard isn't going to take it for sleeping. Howard says that he's an idiot. Leonard corrects him that he is proving a point. Howard asks if the point he is trying to prove is that he is an idiot. Sheldon explains that Leonard it trying to walk a mile in his metaphorical shoes since his feet are too small to fit in his real shoes. Leonard's next step is to go downtown, find the name of the store's former owner and then return the DVD while also paying the fine to prove to Sheldon that you can solve the problem without being a complete lunatic. He now retorts to rubbing his back up and down against the wall. Howard watches Leonard and describes him as a man impersonating a bear who wants you to know that "only you can prevent forest fires". Raj hasn't heard of Smokey the Bear, but he does know Moon-moon the Mongoose who tells you not to play with cobras. Howard is surprised that you have to be taught to not play with cobras. Raj retorts that he had to be taught to not start forest fires.

Amy and Bernie eating all of Penny's food.

Over in Apartment 4B, Amy and Bernadette are scarfing down popcorn and junk food. Penny comes in and tells them if they were hungry, they should have ordered something at the restaurant. Bernie tells her that they did and Penny never brought it to them. She tries to remember their order and gets it wrong. Then she says that she wants to say salmon. Amy retorts that she wants to say sorry. Then they want to know how she is going to deal with Raj since she told Lucy he was a pathetic mess. Lucy then left the restaurant in tears. Penny feels that they are overreacting and Raj is going appreciate her watching his back.

Raj comes over and screams at Penny, asking what is wrong with her. She ended any chance of them getting back together since now she knows he is a desperate mess and previously only thought he was. Raj then gets a text from Lucy asking her to meet him for coffee. Now he loves Penny and gives her a big hug.

Sheldon is in his office working on his white board when Howard comes in. His work involves using virtual photons to study dark energy which Howard thinks is cool. Sheldon then says he needs the opinion of an engineer which Howard is happy to provide. It seems his desk chair is squeaking and he wonders if he should repair it or get a new one. Leonard then comes in and describes his morning activities. He found the name of the DVD store owner and happily says that he died in his sleep at the bottom of a pool some time ago. Since he can no longer return the DVD, he considers the matter resolved. He removes the sweater displaying the rash he developed and puts on a clean T-shirt. Even though the sweater was uncomfortable he did not use it as an excuse to antagonize everyone around him. Howard suggests that he find the store owner's next of kin. Sheldon likes that idea which infuriates Leonard. Howard hands him back the sweater.

At the Wolowitz's Raj is having dinner and wants to know how to handle meeting Lucy. Howard says that he can't let her know he is hurting, try confidence. Bernadette wonders why he wants to see her again since she hurt him so much. Howard explains that Raj has no self-respect and will do anything for affection. Bernadette tells him to relax and see what happens. She says that he can say she looks nice, but only talk about missing her if she asks. She tells him to hold off until the second date his oil painting of them with their children and grandchildren.

Leonard's sweater is still itching.

Over at Penny's apartment Leonard continues to scratch himself while wearing the sweater. Leonard is searching the Internet for a stupid relative of the stupid store owner so he can look at the expression of Sheldon's stupid face. Leonard is practically in tears as Penny tells him to just take it off. For Leonard it's the principle of the thing. Penny is shocked when Leonard shows her his rash. She wants to know if it's made of bees. Penny pleads with him to take it off, but Leonard doesn't want Sheldon to win. Penny reminds him that every night he doesn't kill him in his sleep, he wins. Leonard explains that he is almost done and just has to dispose of the DVD. And wait for someone his complexion to get a skin graft. Penny then takes his picture so he can send it to Princeton University|Princeton and get his money back.

Sheldon is sitting at Amy's place. Amy complements him on handling the DVD situation with an impressive amount of maturity. Sheldon doesn't know why it shouldn't surprise her since he is a grown man so evident by his sport coat and real flower in his lapel. She wonders if it's is a new coping measure he is using. Sheldon wants her to answer the question what does his flower smell like. Amy's answer is "sad". Amy wants to know the real story behind this DVD. Sheldon proposes that he bought a book about how to cope which told he to stop and smell the flowers. Amy asks, "Seriously?" to which Sheldon says please. She leans over and then the flower falls off his coat which is now spotted with water.

At the coffee shop, Raj greets Lucy and tells her how good it is to see her. He ordered her a cappuccino which she remembered as her favorite and also a crumb cake which he later remembered was his favorite and he ate it. First Raj learns that she is doing pretty good. She apologizes for breaking up with him via email. Raj returns that he ate all the crumb cakes, so they both make mistakes. Raj says that he hopes that they can hang out again as friends. Lucy explains that she kind of seeing someone now. Raj needs it explained to him that it's not him that she's seeing.

Raj and Lucy meet for coffee.

Then he is back yelling at Penny that is all her error|fault. He should have listened to Moon-moon and not played with a cobra named Penny. He wonders if she enjoys his pain. She then tells him that she has a friend she can fix him up with. Now he loves Penny again.

Amy and Sheldon are now having tea at Sheldon's place. Sheldon wonders how he can conceptualize dark matter, but not able to fix a novelty squirt flower. Amy says that a better question is why he wastes his time with cheap childish pranks. Then Sheldon offers her some peanut brittle from a can. Leonard storms in telling him that he is out of options. He has found no next of kin. He went to the Armenian church where his funeral was held and found out that no one attended. He did light a candle and prayed for Sheldon's death, but because he is not Armenian, it probably won't work. Leonard says that the search is over. Sheldon suggests that he go to Armenia or Lebanon. He is not going overseas just to return "Super Mario Brothers: The Movie". Finally he asks Sheldon why the DVD is not bothering him and why his brain isn't getting itchy. The DVD was checked out on his card and could be ruining his credit score. Sheldon has to admit something to him and he asks Leonard to not flip out. Seven years ago he found out it was late and paid for it. He was going to mention it then, but he thought that someday this time could be a teachable moment. Hearing this comment, Leonard goes berserk - he rips off the sweater and hurls it in the trash, before yanking the freezer door open and pulling out a couple of frozen food packs to apply to his chest. He then heads to his room, but returns momentarily, too flabbergasted to speak, eventually managing to get out the word "What!!!" Amy then comments that the whole thing was diabolical. Sheldon agrees and then asks if she knows what it is like to wait for years never knowing if you'll finally get satisfaction. Amy just stares at him and says nothing. The look on her face says she’s about waiting for years and getting no satisfaction.

Raj is on his date telling the Indian girl that she is so pretty he can't believe she doesn't have a boyfriend, which she doesn't. Then Raj explodes that he doesn't believe her and accuses her of lying to him. Then he says that he is so desperate, which he is willing to be the man she has on the side. Then the girl is screaming at Penny, "What is wrong with you?" Then Penny is screaming at Raj, "What is wrong with you?" Finally Raj is screaming at a mirror, "What is wrong with you?"



  • Jesse Schedeen for IGN - The sweater conflict... just kept building and building until Sheldon dropped his final bombshell and Leonard was reduced to incoherent rambling. Simple, yes, but this episode did a great job of steadily building up a gag and then paying it off nicely in the end...The other half of the episode focused on the Raj/Lucy relationship. Given how abruptly Lucy was written out of the show at the end of Season 6, I was glad to see some actual closure this time...But really, it was Amy who had the coup de grace this week..."Do you have any idea what it's like to wait for years and never know if you're going to finally get satisfaction?" Amy's silent look was priceless.
  • Dhruv Rao of The DR Club gave the episode a B [1]
  • IMDb user reviews


  • Title Reference: Sheldon describes to Leonard how an urge/itch or obsession gets caught in his brain, so he makes Leonard wear an itchy sweater to make him feel what that itch is like. It is also a punishment for a previous indiscretion.
  • Taping date: October 29, 2013.
  • Chuck Lorre's vanity card. [2]
  • This episode was watched by 18.30 million people with a rating of 5.2 (adults 18–49).
  • Total viewers including DVR users 23.34 million.
  • The Big Bang Theory was ranked #3 for the week ending November 17, 2013.
  • This episode aired in Canada on November 14, 2013, with 3.547 million viewers with a weekly ranking of #1.
  • In the United Kingdom, this episode aired on January 16, 2014, with 2.07 million viewers and a weekly ranking of #1.
  • In Australia, this episode aired on January 28, 2014, with 1.26 million viewers.
  • Episode transcript [3]

Costume Notes

  • Sheldon wears his Hawkman logo t-shirt, and his blue Vetrivian Superman t-shirt from Fat-Tee.
  • During her date with Leonard, Penny wears a dark floral, Veronica Cap Sleeve Dress by Parker, available at (originally at Bloomingdales).
  • Penny wears a blue boat-neck long sleeved snake print tee by Michael Stars (sold at Bloomingdale's).
  • It's no wonder Penny has been perpetually broke...her beaded moccasins by Joie Aliso sell for about $225 at ShopBop.


  • Sheldon ponders, "How is it I can conceptualize a methodology of examining dark matter in the universe, but can't figure out how to fix a novelty squirt flower?" Given he would certainly be referencing his current work, an erroneous substitution of dark matter in place of dark energy was made.
  • An explanation is provided for why the dartboard behind the door of Apartment 4A is never used.
  • Sheldon claims that unresolved issues are uncomfortable for him, like an itch in his brain that he can't scratch. This action is consistent with his closure obsession, the main topic of "The Closure Alternative" (S6E21). And it seems the former provides a plausible explanation for the latter.
  • This episode is not the first time that Sheldon overreacts to minor issues concerning DVDs or Blu-rays etc., and this time he describes such an issue as "uncomfortable unresolved issues". Thus, it seems to be a plausible hypothesis that the previous similar minor DVD or Blu-ray issues, such as those happened in "The Apology Insufficiency" (S4E7) and "The Romance Resonance" (S7E1), might have bothered Sheldon out of similar reason. In "The Hofstadter Insufficiency" Sheldon's nightmare begins with him discovering that the "Back to the Future" DVDs have been swapped.
  • Penny again tells everyone she is a terrible waitress. Last time she said this comment in "The Habitation Configuration" (S6E7).
  • Penny finally meets Lucy and says she expected her to be Indian (Previous to this episode only Raj and Amy in the gang have met her, while Leonard and Sheldon have seen her in the comic book store, and Stuart and Howard have spoken to her). The girls tell Penny that her attitude is racist.
  • Sheldon buys a squirting lapel flower that breaks and he can't fix it.
  • As of this episode, all of the gang have now met or seen Raj's ex-Lucy.
  • Sheldon had waited seven years for a chance to use the "Super Mario Bros. (film)|Super Mario Brothers: The Movie" DVD situation.
  • The guys' fear of spiders have been mentioned twice before in "The Dead Hooker Juxtaposition" (S2E19) and "The Bon Voyage Reaction" (S6E24).
  • Lucy doesn't run away during two emotional scenes, and she requests to change the waitress when Penny talks about the Raj issue with her. It is obvious that like Raj (who overcame his selective mutism towards women), she has improved emotionally since last season.
  • Leonard complained previously about an itchy garment in "The Vartabedian Conundrum" (his pants) purchased by his girlfriend Doctor Stephanie.
  • Second episode where a main character borrows Sheldon's Type A personality while he remains calm. First was "The Financial Permeability".
  • Second episode where a main character soothes their pain delivered by another main character with a frozen bag of peas. First was "The Porkchop Indeterminacy".
  • Bernadette's lab is mentioned, but is not seen in the actual show since the times at her workplace in Zangen since two season 6 episodes of "The Higgs Boson Observation" (S6E3) and "The Santa Simulation" (S6E11). It also happens in the season 8 episode of "The Junior Professor Solution" (S8E2).
  • When Leonard is scratching his back on the beam, Howard makes a reference to Smokey the Bear. But it was actually Baloo he was unintentionally imitating.


Leonard: Oh. I forgot about this. My aunt made it for my when I started college. [Holds up a red sweater with ‘Lenny’ sewn into the front.]
Penny: Ah. Did she hate you?
Leonard: Why? Because I got an ugly itchy sweater and my brother got a car? No..I was her favorite.

Amy: My God, that’s the girl that broke Rajesh’s heart.
Bernadette: That’s Lucy?
Penny: I don’t know why, but I always pictured her as Indian.
Bernadette: I think reason is called racism.
Penny: I’m going to talk to her.
Bernadette: Why? What are you going to say?
Penny: I’m not going to say anything. I’m going just want to talk her out. She hurt my friend. My Indian friend. Who’s racist now?
Bernadette: You. Because you just called him your "Indian friend".
Penny: Yeah, well, you’re short.
Amy: We’re never getting our drinks.
Bernadette: No, but we knew that.
Penny: Hi. Can I start off with something to drink?
Lucy: Oh, water would be great.
Penny: Okay. Um, you’re Lucy, right? I’m a friend of Rajesh Koothrappali. You see, Amy recognized you.
(Amy and Bernadette are seen pouring bar drinks into glasses; they wave to Penny and Lucy)
Lucy: Wow, how’s he doing?
Penny: Oh, you know. He’s good.
Lucy: Great.
Penny: Yeah. This is none of my business, but why did you break up with him in an email?
Lucy: Um, I don’t know. I guess I thought it would be easier.
Penny: Yea, I get that. I’ll go get you your water. (starts to leave, but comes back) When you say easier, you mean easier for you, right? Cause it certainly didn't make it easier for him.
Lucy: Any chance I can get a different waitress?
Penny: I’m sorry, it’s rude of me. I will get you that water. (starts to leave, but comes back) See, see, see, see. Just now, you expressed your feelings to my face. How come you can do that with me, and not with Raj?
Lucy: I don’t know your email.
Penny: You know what the worst part is? You’re sitting here perfectly happy and he’s at home a blubbering mess.
Lucy: I thought you said he was okay.
Penny: Well, I also said I was getting your water, but look at me; still standing here. You know, maybe I’m a bad waitress, but you’re a bad person. Now, you want to hear the special?

Sheldon: And second, you completely disregard how uncomfortable unresolved issues are for me. It’s like an itch in my brain I can’t scratch.

Raj: How are you?
Lucy: I’m pretty good. Listen, I just wanted to apologize for breaking up with you in an email.
Raj: And I ate all the crumb cake. We both make mistakes.
Lucy: Okay.
Raj: I’m so happy you asked me here and I hope we can hang out again sometime you know as friends…love making partners…whatever.
Lucy: I’m kind of seeing someone.
Raj: I think I know the answer to this, but to be clear; it’s not me right?

Penny: Oh my God. Is the sweater made of bees?

Penny: Smile.
Leonard: What is that for?
Penny: So you can send it to Princeton and get you money back.

Leonard: Why isn't this bothering you? Isn't your brain getting itchy? This is on your card. This could be ruining your credit score. Why isn't this making you crazy?
Sheldon: I have something to tell you, but I want you to promise not to flip out.
Leonard: What?
Sheldon: Seven years ago I found out the DVD was late and I paid for it.
Leonard: What?
Sheldon: I was going to mention it at the time, but then I thought someday this might be a teachable moment.
Leonard: Ahhh! I.. You..Ah…WHAT??
Amy: Sheldon, that was diabolical.
Sheldon: I know. And it wasn't easy. Do you have any idea what it’s like to wait for years and never know if you're going to finally get satisfaction?
Amy: [stares silently]

  • “What is wrong with you??” [Repeated line by several characters.]

Howard: [Leonard is scratching his itchy sweater] So you can never take it off?
Leonard: No.
Raj: Not even to sleep?
Leonard: No.
Howard: So you’re just an idiot.
Leonard: It’s called proving a point.
Howard: Is the point you’re an idiot?