Sheldon: Mmm. [in Mandarin] Your monkey sleeps inside me.

Sheldon: I feel renewed. I'm ready to deal with any changes that come my way. [sees Penny] Your hair is different. You changed your hair. I can't take this. I'm out.

Mary Cooper: Thank you, God, for the food we are about to receive and for the nourishment of our bodies and bless the hands that prepared it. Amen.
Sheldon: Given that your hands prepared it, isn't that a little self-serving?
Mary Cooper: You start changing the words to the prayers, next thing you know, you're in a church with a guitar.

Leonard: Howard, could I borrow some after shave?
Howard: Black case, top compartment.
Leonard: That is a lot of cologne.
Howard: First row are your musks, second is wood, leathers and botanicals, third is assorted pheromones, tread lightly.

Sheldon: Who's ready to laugh? [Leonard groans] Okay. So Feynman, Einstein and Schrodinger walk into a bar. Feynman says, "It appears we're inside a joke." Einstein replies, "But only to an observer who saw us walk in simultaneously." To which Schrodinger says, "If someone's looking in the window, I'm leaving."
Leonard: [chuckles] That's actually funny.
Raj: You should send that to Jimmy Fallon.

Georgie: You went away to college after Dad died. Who do you think took care of everything?
Sheldon: Mom did. Mom always took care of everything.
Georgie: Mom was a mess, Missy was a dumb teenager. I had to look after both of 'em.
Sheldon: I talked to Mom all the time. If she was upset, she would have told me.
Georgie: She was protecting you, you idiot, just like everyone always does.
Sheldon: If things were bad, then why didn't you tell me?
Georgie: Because I was protecting you, too. (sighs) You're my baby brother, Sheldon. I know life has been hard for you, but that don't mean it's been easy for the rest of us.

Penny: God, you know, I have been in L.A. for almost two years now, and I haven't got a single acting job. I have accomplished nothing, haven't gotten a raise at work, haven't even had sex in six months, and just now when I was walking up those stairs a fly flew in my mouth and I ate it.
Sheldon: Well, actually, insects are a dietary staple in many cultures. They're almost pure protein.

Sheldon: Professor, can you identify our cricket?
Crawley: Of course I can. I can identify every insect and arachnid on the planet. Not that that's gonna keep me from having to move in with my daughter in Oxnard. And we're not talking Oxnard at the beach. No, we're talking Oxnard in the onion fields!

Leonard: What would I even say?
Sheldon: "Zack, I'm sorry you're stupid. Have a Milk Dud."
Raj: A Milk Dud?
Sheldon: Yeah, Milk Duds, with their self-deprecating name and remarkably mild flavor, are the most apologetic of the boxed candies.
Leonard: I got a better idea. Were all responsible. I say we all go. Come on, who's with me? Free comic books to anyone who comes with me. I might get punched. You really want to miss that?
Raj: Junior Mints are pretty apologetic.
Sheldon: You're embarrassing yourself.

Bernadette: Sheldon, when was the last time you got any sleep?
Sheldon: I don't know. 2 or 3 days. Not important. I don't need sleep, I need answers. I need to determine where in this swamp of unbalanced formulas squatteth the toad of truth.
Penny: Toad of truth? Is that a physics thing?
Leonard: No, that's a crazy thing.

Sheldon: What is the best number? By the way, there's only one correct answer.
Raj: 5,318,008?
Sheldon: Wrong. The best number is 73. [short silence] You're probably wondering why.
Leonard & Howard: No, no, we're good.
Sheldon: 73 is the 21st prime number, its mirror 37 is the 12th and its mirror 21 is the product of multiplying, hang on to your hats, 7 and 3. Did I lie?
Leonard: We get it. 73 is the Chuck Norris of numbers.
Sheldon: Chuck Norris wishes. In binary, 73 is a palindrome, 1001001, which backwards is 1001001, exactly the same. All Chuck Norris gets you backwards is Sirron Kcuhc.
Raj: Just for the record, when you enter 5,318,008 in a calculator, upside down it spells boobies.

Penny: Helium.
Sheldon: Yes.
Penny: Yes.
Sheldon: Taylor Swift.
Penny: Yes. Pi.
Sheldon: Yes. Kardashian.
Penny: More specific.
Sheldon: Khloe?
Penny: Yes.
Sheldon: See, I remembered because if it looks like Kim it's Kim, if it looks kind of like Kim it's Kourtney, and if it looks nothing like Kim it's Khloe.

Sheldon: And look over here, "shrimp in mobster sauce". What is mobster sauce?
Leonard: It's obviously a typo.
Sheldon: Perhaps. Perhaps this restaurant's now a front for organized crime. For all we know, the mobster sauce contains actual chunks of deceased mobsters.
Raj: No, no, no, no. I think it jut means it's the kind of sauce that mobsters like.
Howard: It doesn't mean any of that. It's a typo!

Sheldon: Under normal circumstances I'd say I told you so. But, as I have told you so with such vehemence and frequency already, the phrase has lost all meaning. Therefore, I will be replacing it with the phrase, "I have informed you thusly".

Amy: Do you need anything else?
Sheldon: You know exactly what I need.
Amy: Fine. [sings and plays autoharp] Soft kitty, warm kitty, little ball of fur. Happy kitty, sleepy kitty, purr, purr, purr.
Sheldon: That's nice. Now in German.
Amy: [sings and plays autoharp] Weiches Kätzchen, warmes Kätzchen, das nie und nimmer murrt. Liebes Kätzchen, müdes Kätzchen, schnurrt, schnurrt, schnurrt.
Sheldon: Great. Now Mandarin.
Amy: [sings and plays autoharp] Ruǎnmiánmián de xiǎo māomī máoróngrōng, kuàilè kēshuì qīngqiǎo māomī, gūlǔ gūlǔ gūlǔ.
Sheldon: Now Navajo.