Amy: Okay, smart guy. I'm about to remove the locus coeruleus, which is incredibly delicate work. Have at it.
Sheldon: All right. I'm no stranger to a little gray matter. Locus coeruleus. Locus coeruleus.
Amy: You're getting warmer, it is, indeed, in the brain. Hope your hands are steady. It's the width of a single hair. But this is just biology, so I'm sure it's no problem for a genius like you.
Sheldon: It's not. I'll have you know, in the field of physics, we work with particles so small, they make fat jokes about the locus coeruleus, i.e., when your locus coeruleus sits around the house, it sits around the house.

Raj: I don't like bugs, okay. They freak me out.
Sheldon: Interesting. You're afraid of insects and women. Ladybugs must render you catatonic.

Sheldon: Scissors cuts paper, paper covers rock, rock crushes lizard, lizard poisons Spock, Spock smashes scissors, scissors decapitates lizard, lizard eats paper, paper disproves Spock, Spock vaporizes rock, and as it always has, rock crushes scissors.

Sheldon: Why are you crying?
Penny: Because I'm stupid.
Sheldon: That's no reason to cry. One cries because one is sad. For example, I cry because others are stupid, and that makes me sad.

Howard: I'm not signing a prenup.
Penny: All right, Howard Wolowitz, listen up! You sign anything she puts in front of you, because you are the luckiest man alive. If you let her go, there is no way you can find anyone else. Speaking on behalf of all women, it is not going to happen, we had a meeting.

Penny: So you're saying if I became a famous movie star, we got married, you wouldn't sign a pre-nup?
Leonard: Absolutely not! If I'm gonna be stuck at home with the kids while you're on location cheating on me with Ryan Gosling, then Leonard gots to get paid.

Penny: Hey, what are you guys doing here?
Howard: We're grown men, we drink at bars.
Penny: No and no. Everything okay with you and Bernadette?
Howard: Oh yeah, sure.
Penny: You and Amy? Good?
Sheldon: Oh, better than good.
Penny: You know those girls text me every detail of their lives as it happens.