Sheldon: How much will it hurt?
Amy: It's just a tiny skin sample. You saw me do it to myself.
Sheldon: On a scale of one to ten, where one is a pebble in your shoe and ten is the monkey you thought was your pet biting your face off.
Amy: A two.
Sheldon: Eating a whole Altoid?

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: Still, I can't believe you can turn ordinary skin cells into functioning brain cells.
Amy: Well, I turned this one into a functioning boyfriend, so sky's the limit.

Raj: Well, I can't eat like a ten-year-old all the time.
Penny: You're dating somebody! Who is it?
Raj: What? What are you talking about?
Penny: You only watch what you eat when you're afraid you might have to take your shirt off.

Raj: Maybe there are other things we have in common. Come dinner-time, do you enjoy eating food?