Leonard: We did them at Princeton, too.
Howard: Oh, that's cute. Like it's a real college.
Sheldon: That's amusing. I was going to say the same about M.I.T., but it works for Princeton, too.

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.

Penny: [to Raj] Run to India.

Amy: As my mom used to say, "When you're doing a puzzle, it's like you've got a thousand friends." She was full of fun lies like that.

Bernadette: (Shouting at another driver) Your kid might be a honor student but you're a moron!