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: 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: 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.

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

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: (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.

Penny: Hey! Shouldn't you be out with your gang spray painting equations on the sides of buildings?