Sheldon: What happened to me? I used to excel at these things.
Howard: Kids are always better at video games.
Sheldon: Well, I don't like it.
Leonard: If it makes you feel better, you still dress like a child.

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: Physicist, baker, lover, what can't I do?

Penny: I didn't know you could drink while you were breastfeeding.
Bernadette: Yeah, they say the yeast in beer helps with milk production.
Amy: I'm pretty sure that's a myth. Let me check.
Bernadette: Ruin it for me, and I'll break this glass over your head.

Penny: You want food?
Bernadette: Yeah, breastfeeding burns, like, 5,000 calories a day. (To Amy) Do not touch that phone!