Leonard: Who are you talking to?
Penny: Oh, just this guy I met at school.
Leonard: oh, great. We're still dating, right?
Penny: Relax. He's just a friend. We're doing an oral report together. He's really nice.
Leonard: I'm sorry, what was that? I had a little stroke after oral.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Leonard: What would you be if you were attached to another object by an inclined plane, wrapped helically around an axis?
Sheldon: Screwed?
Leonard: There you go.

Leonard: My point is, while you're spending all this time on your own, building computers or practicing your cello, what you're really doing is becoming interesting. When people finally do notice you, they're gonna find someone a lot cooler than they thought. And for those of you that were popular in high school, it's over, sorry. Thank you. Congratulations.

Sheldon: You may not realize it, but I have difficulty navigating certain aspects of daily life. You know, understanding sarcasm, feigning interest in others, not talking about trains as much as I want. It's exhausting!

Sheldon: I'm not saying you don't have attractive qualities. Your choice of friends is impeccable, you're a good sleeper, and last but not least, you buy the grapes I like. You're a real catch compared to some snoring guy with a fridge full of lousy grapes.

Sheldon: (Playing hackey sack) One, two, three, four, five, six, seven, eight. Drat. I'm never going to get to forty-three again. One, two, three, four. Rats.