Raj: Sheldon, you busy?
Sheldon: I'm always busy. This mind is capable of advanced multi-tasking. Currently, I'm attempting to solve the Penrose Conjecture, I'm composing my Nobel acceptance speech for when I've solved the Penrose Conjecture, and I'm wondering how mermaids have babies.

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: Are they making fun of us?
Raj: Yep.
Sheldon: I miss the old days when I couldn't tell.

Bernadette: Speaking of new careers, how are things going with dark matter, Sheldon?
Sheldon: Oh, I have to say it's the most exciting time in the history of the field.
Bernadette: Oh, what's going on?
Sheldon: I started doing it.

Penny: Hang on. You guys are going to work in a mine?
Sheldon: Why not?
Penny: You had a panic attack when we went through the car wash!