Penny: Okay, listen, there's something I need to tell you. I've been thinking about going back to school for a while now. So a couple months ago, I started taking a history class at the community college.
Leonard: Oh. That's great. Great, great, great. Why wait so long to tell me?
Penny: I don't want you to make a big deal out of it.
Leonard: Why do you think I'd be like that? I get it, you're taking one class. It's nice. Maybe if it goes well, you take another, you enroll full-time. Ooh, be sure to keep an eye on which credits transfer to a four-year college.
Penny: You're making it a big deal.
Leonard: Sorry. (nonchalantly) Whatever. It's all good.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Howard: Don't feel bad. Some day someone will be throwing out your work, too.
Leonard: That someone was Sheldon and the day was yesterday.

Sheldon: I remember the song! It's called "Darlin'" by the Beach Boys! Oh, thank goodness! I'm not crazy! I don't have to take a pigeon as my bride!
Leonard: There goes our shot at him living on the roof.

Leonard: I did a bad thing.
Sheldon: Does it affect me?
Leonard: No.
Sheldon: Then suffer in silence.

Stephen Hawking: What does Sheldon Cooper and a black hole have in common? They both suck.

Sheldon: Steven Hawking's a genius and he talks like a robot. It's everything I ever wanted in a friend.