Sheldon: Beverly believes I unconsciously consider my old room an escape hatch.
Amy: Is that bothering you?
Sheldon: Yes. I don't care for unconscious thoughts. My brain and I are best friends. It should tell me everything.
Amy: I mean, how it relates to our relationship, not the bromance between you and your brain.

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.

Raj: I'm sorry, guys. Sheldon was upset, Leonard and Penny were fighting. I just wanted to go someplace where I wasn't causing problems.
Howard: (sighs) I'll say it again. India.

Sheldon: What if she's correct? Doesn't that say something troubling about us?
Amy: I don't know. I just think you're the kind of person who likes a contingency plan.
Sheldon: That is true. Did you know I figured out in which order I would eat all my friends in the event of an apocalypse?
Amy: You need to stop hanging out with your brain so much. It's not a good influence.

Penny: Well, it's like that science thing. For every action, you have a gigantic and annoying reaction.
Leonard: Just when I thought you couldn't get any hotter.