Amy: Hey.
Sheldon: Hello.
Amy: "Fine with flags"?
Sheldon: Yes, flags, up there flapping around on poles. If you think about it, they're just the strippers of the emblem world.

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.

Sheldon: Thanks, Dad. We're gonna give them hell.

Leonard: I have something that might help. It's-it's a recording of the only person whose opinion Sheldon actually respects.
Amy: Hawking? Feynman?
Leonard: No, himself.

Leonard: It's a pep talk he made when he was a kid. He gave it to me years ago and told me to save it for a real emergency.
Penny: What? You didn't break it out when he declared his room a sovereign nation and waged a trade war against us?
Leonard: His major export is talking. I didn't want that anyway.