Ramona Nowitzki: Are these all from Peter Higgs?
Sheldon: Hmm? Oh, no, no, no. They're from many famous people. See? Oh, like this one. This is from Patrick Stewart. It says if I come to his house again, I get to meet his dogs.

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.

Amy: I gave you one job! Keep an eye on him. How hard is that?

Sheldon: Because there's only one of me, I'm more valuable.
Penny: Right.
Sheldon: Although, Amy's already taken me out of my package and played with me.

Amy: Why didn't you tell me?
Bernadette: We didn't want you to worry.
Amy: Should I worry?
Penny: No, come on, it's Sheldon. Nothing is gonna happen.
Amy: That's what you said to me when I started dating him. And then five years later, bingo-bango, something happened.