Adult Sheldon: Not all science is created equal. There's physics, the undisputed king of science. There's chemistry. It's no physics, but it's not a bad way to pass a rainy afternoon. And then there's biology, the squishiest of the sciences.

Adult Sheldon: I didn't realize until years later that my father was only asking questions about lightning and thunder to cheer me up. In fact, he would often pretend to be dumb just to make me feel better.

Adult Sheldon: My father didn't always get the credit he deserved. The advice he gave me actually worked out pretty well. Of course, I never told him.
George: Talked to Billy.
Missy: Why would you do that?
George: No, it was good.
Missy: Stay out of my life.
Adult Sheldon: He may not have been the world's greatest dad. But maybe we weren't the world's greatest kids.

Adult Sheldon: Ignoring things that irritate me isn't my strong suit. Obsessively fixating on them, now that's what gets me out of bed in the morning.

Sheldon: Mr. Givens, I just wanted you to know that I'm still working hard on my campaign to get more funding for the science department.
Mr. Givens: Oh, great, 'cause I've got to dig up tomorrow's worms myself.

Principal Petersen: [screams]
Sheldon: [screams]
Principal Petersen: What are you doing, standing there?
Sheldon: I wrote a formal complaint letter to the school board on how much money is spent on football. I was hoping you could deliver it to them.
Principal Petersen: You do realize your father's a coach here.
Sheldon: Yes, sir, I do.
Principal Petersen: Maybe you ought to talk to him about this first.
Sheldon: I did. He didn't care for the idea at all.
Principal Petersen: Well, there you go.
Sheldon: There I go what?
Principal Petersen: Let me see that. "Barbaric sport encourages bloodlust similar to Roman gladiator games Christians, lions money better spent on science and learning." You're joking, right?
Sheldon: Did you see the word "bazinga" anywhere in that letter?
Principal Petersen: Out.

Sheldon: Hello, I'd like to speak to the mayor, please. My name is Sheldon Cooper. I'm running for class president and was hoping he could give me some advice. I'm ten years old. But if it helps get him on the phone, I'm well-behaved, a straight-A student, and have impeccable hygiene.