Leonard: My dad was an anthropologist. The only father-son time he spent was with a 2,000-year-old skeleton of a Etruscan boy. I hated that kid.

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: You know, its a tad old-school, but my father was not one to spare the rod when my brother would sneak into his truck and drink his driving whiskey.
Amy: You want to spank me?

Amy: I don't need your medicine. I'm not really sick. I got better two days ago.
Bernadette: I don't understand.
Amy: It's been so nice having Sheldon take care of me, I just wanted that to last longer.
Bernadette: You should tell him.
Amy: I know.
Sheldon: (From the other room) Amy! Are you strong enough to bathe yourself, or do you need my help?
Amy: I'll tell him tomorrow. Mama needs a bath.

Sheldon: Amy's taking me to a memorial service. It's for one of her colleagues who is of Asian descent, so my planned conversational gambit is to casually remark that no matter how deep they dig his grave, he'll never make his way back to China.
Leonard: That should lighten the mood.
Sheldon: What can I say? I put the fun in the funeral.