Sheldon: Physicist, baker, lover, what can't I do?

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: I didn't know you could drink while you were breastfeeding.
Bernadette: Yeah, they say the yeast in beer helps with milk production.
Amy: I'm pretty sure that's a myth. Let me check.
Bernadette: Ruin it for me, and I'll break this glass over your head.

Penny: You want food?
Bernadette: Yeah, breastfeeding burns, like, 5,000 calories a day. (To Amy) Do not touch that phone!

Penny: Uh, what's new?
Zack: Oh, tons of stuff. Put artificial grass in my backyard, got engaged, had a scary mole that turned out to be Sharpie.
Penny: Well, congratulations.
Zack: That's what my dermatologist said.
Penny: No, on getting engaged, good for you.
Zack: Oh, thanks.