Sheldon: Oh, no.
Leonard: What's the matter?
Sheldon: I forgot my flash drive.
Leonard: So?
Sheldon: So we have to go back.
Leonard: Okay, Sheldon, I'm going to say why and your answer cannot be because I forgot my flash drive.
Sheldon: You don't understand. My flash drive has my paper on astrophysical probes of M-theory effects in the early universe that I was going to give to George Smoot at the conference.
Leonard: Why do you have to give your paper to George Smoot?
Sheldon: It's brilliant. He needs to read it.

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: She calls me moon-pie because I'm nummy-nummy and she could just eat me up.

Leonard: Well, it looks like you're caught between a rock and a crazy place.
Sheldon: I hate when that happens.

Sheldon: No one calls me Moon Pie but Meemaw.