Sheldon: Oh, but don't worry. I won't do that to you.
Amy: Maybe you should.
Sheldon: What?
Amy: This has been your lifelong dream. And you may not get another chance. I don't want to be the reason that you don't win a Nobel.
Sheldon: You're the only reason I deserve one.

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.

Bernadette: Look at Howard. He was a disaster when I met him. Now he's a foxy astronaut with a hot wife.
Raj: Wait, he always wanted to be an astronaut.
Bernadette: He thinks that, too. That's how good I am.

Penny: No, it's not that.
Bernadette: Then why?
Penny: Honestly, I don't know if I'm up to it. You know, the last project I managed was my high school yearbook.
Bernadette: And?
Penny: And that was the year we didn't have one. - And? And that was the year we didn't have one. Apparently, the printers won't make them without getting paid.
Bernadette: What happened to the money?
Penny: Uh, if I didn't know then, I'm not going to magically know now.

Amy: What's wrong?
Sheldon: Why do you assume something's wrong?
Amy: Because you haven't touched your dinner, and you're literally ticking like a bomb about to go off.
Sheldon: Oh, Amy. You see through me like one of Penny's shirts.