Amy: Well, as much as we've studied the brain, there's still a lot we don't know about dreams and their function. You know, even psychologists are divided on it.
Leonard: Mm, it's true. Freud thought dreams were about sex, Adler thought they were about dominance-
Penny: Then again, mine are just about being married to this little guy.
Leonard: Well, now it's just edging into mockery.

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?

Bernadette: One of the great things about being pregnant is drinking cranberry juice out of a wineglass and watching people freak out.

Penny: Is it possible that you're stressed because you're scared about getting married? I mean, it is a big change, and you're not good with little changes.
Sheldon: Well, that's nonsense. You name one little change I was upset with.
Penny: Uh, when they changed the green Skittle from lime to apple.
Sheldon: That is not the rainbow I grew up tasting.

Howard: It's a date. Just pick one.
Sheldon: It's not just a date, it's a textbook optimization problem. There is a perfect date. Just like there's a perfect room temperature and a perfect dessert.
Penny: Mm. There's no perfect dessert.
Sheldon: Yellow cake in the shape of a dinosaur with chocolate frosting, a scoop of vanilla ice cream on the side, not touching. You'll see. You'll have it at our wedding.
Amy: You wanna bet?