Leonard: Damn, I need my inhaler.
Penny: Just don't smoke.
Leonard: No, I went down the stairs too fast.

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.

Amy: What is this?
Sheldon: A functional MRI of my brain. I did Sudoku before they took it so I'd be ripped.
Amy: I love it. Thank you.
Sheldon: And it's not just an MRI. The orbitofrontal cortex is lit up because I was thinking of you.

Penny: Howard and Bernadette's kid might be born on your birthday. How cool is that?
Amy: Yeah, but I thought this baby was supposed to ruin their sex life, not mine.

Raj: Don't come to the hospital. We're headed home.
Penny: Oh, that was fast. Did she sneeze the baby out?