Penny: I just want to know why a five-year-old boy puts on his mom's make-up and wears balloon boobies.
Leonard: They weren't boobies, they were muscles. And the make-up was green, I was pretending to be The Hulk.
Penny: You were wearing her bra.
Leonard: That was to keep my muscles from sagging. Can we please stop talking about this?!

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.

Raj: In the last hour 162 people have read our profiles. How many of them have sent us messages?
Stuart: Combined?
Raj: Yes.
Stuart: Zero.

Sheldon: You've spent time with Amy, can you think of anything she's fond of that has a bunch of flaws she hasn't noticed?
Leonard: ... I got to go.

Sheldon: Amy ruined Raiders of the Lost Ark for me, so I'm trying to find something beloved of hers and ruin that.
Howard: Because her life wasn't enough?