Raj: So am I gonna be, like, the only single guy at Sheldon's wedding?
Leonard: No. There-There'll be a lot of single people there. Stuart, Amy's great-aunt. Although, Stuart's already friended her on Facebook, so, better move quick.

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.

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.

Georgie: After all my sacrifices, guess which kid my mom is the most proud of?
Leonard: If it makes you feel any better, my mom's most proud of Sheldon, too.

Georgie: You went away to college after Dad died. Who do you think took care of everything?
Sheldon: Mom did. Mom always took care of everything.
Georgie: Mom was a mess, Missy was a dumb teenager. I had to look after both of 'em.
Sheldon: I talked to Mom all the time. If she was upset, she would have told me.
Georgie: She was protecting you, you idiot, just like everyone always does.
Sheldon: If things were bad, then why didn't you tell me?
Georgie: Because I was protecting you, too. (sighs) You're my baby brother, Sheldon. I know life has been hard for you, but that don't mean it's been easy for the rest of us.

Georgie: Leonard, you know how I got the money to open up my first store? I busted my ass for it, 'cause all the extra money that we had had to go to Sheldon so he could go to college and he could go study in Germany. And do you know what he's never said to me?
Leonard: Danke schon? It's, uh, "thank you" in German.
Georgie: Do you need me to sit on your head?
Leonard: Nope.