Leonard: Okay, at some point, we'll look back and this is going to be a funny story. Why don't we just start doing that now?
Penny: You're kidding.
Leonard: No. Hey, do you remember that time when I proposed to you in bed? And you were all, like, what are you doing? That was so funny. So funny.
Penny: It's not funny.
Leonard: Give it a minute. Is that a little smile I see there? I should 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.

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.

Mr. Rostenkowski: Walnut?
Howard: No, thank you. I'm allergic.
Mr. Rostenkowski: Oh, sure. My partner used to have that. He's dead now.
Howard: From nuts?
Mr. Rostenkowski: Nah, his wife shot him. But she was nuts, so in a way.

Mr. Rostenkowski: It's gonna be okay, son.
Howard: You really think so?
Mr. Rostenkowski: Of course. A pretty girl like Bernadette, she'll find a new guy.

Amy: We're playing doctor. Star Trek style.