Sheldon: The Air Force did it again. They're erasing our lives!
Leonard: Third floor, wrong apartment.
Howard: Although, if anyone's gonna clean out your apartment and disappear, it'd be Penny.
Leonard: She might disappear, but she's definitely not cleaning anything.

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: And just remember, I am proud of you and I support you in all that you do.
Amy: Thank you. That means a lot.
Sheldon: Oh, and one last thing. If you find yourself working with a male scientist who's as smart as me, as tall as me and has hair like Thor, well, then I want you to step away from the situation and call me immediately.

Raj: I really can't thank you enough for taking me in. You know, I was in a pretty low place in my life, and-
Sheldon: (from across the hall) Oh, Amy, you naughty vixen.
Raj: Anyway, uh, as I was saying, I was at a pretty low place in my life and, uh, if it wasn't for friends like you-
Amy: (from across the hall) My goodness, that form of stimulation is highly efficient.
Raj: I can't compete with that.

Howard: Well, why would you do that?
Colonel Williams: You guys completed phase one, we'll take it from here.
Sheldon: Where did you move it?
Colonel Williams: I can't tell you that.
Leonard: Are you implementing phase two?
Colonel Williams: I can't tell you that.
Sheldon: Wait, so you're just going to take all the work we've done for the last year and toss us aside?
Colonel Williams: That one I can tell you, yes.
Howard: This is all very upsetting.
Colonel Williams: I'm sorry to hear that. As you know, the primary focus of the United States military is people's feelings.
Sheldon: If that's sarcasm, please save it for our enemies.