Amy: Watching your old friend?
Sheldon: Yes. Look at him, Amy. It's such a shame. Struck down in the prime of my life.

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: I know why. You've come to me because you're my Obi-Wan.
Arthur: I'm not familiar with that. Is that an Internet?

Amy: I guess it must have been back when I was in the Girl Sprouts.
Bernadette: Girl Sprouts?
Amy: My mom made it up as an alternative to the Girl Scouts. She didn't want me selling cookies on some street corner like a whore.

Penny: Oh, I get it. Like C-3PO. ... What happened to me?