Sheldon: I'd love to see a scan of your brain sometime.
Beverly Hofstadter: Oh, I'll send you a link, but its physiology is fairly unimpressive.
Sheldon: Oh, I can't believe that.
Beverly Hofstadter: Your unwillingness to accept empirical evidence suggests an attempt at flattery.
Sheldon: My apologies. I've been living with your son too long. Gotten into some bad habits.
Beverly Hofstadter: Understandable.

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.

Beverly Hofstadter: It might explain why the two of you have created an ersatz homosexual marriage to satisfy your need for intimacy.
Howard: Say what?

Leonard: She's only been here a day and a half, and I'm seriously considering alcoholism as a new career path.
Penny: Hey, I talked to her for five minutes yesterday, and I've been half bombed ever since.

Penny: I'm curious. What was Leonard like when he was little?
Beverly Hofstadter: I think you mean young. He's always been little.