Penny: Or you accomplished something great, and she's genuinely proud.
Leonard: [taking Penny's wine glass] Yeah, all right, you've had enough.

Sheldon: I remember the song! It's called "Darlin'" by the Beach Boys! Oh, thank goodness! I'm not crazy! I don't have to take a pigeon as my bride!
Leonard: There goes our shot at him living on the roof.

Howard: Don't feel bad. Some day someone will be throwing out your work, too.
Leonard: That someone was Sheldon and the day was yesterday.

Professor Proton: Can I ask you a question?
Leonard: Yeah, sure.
Professor Proton: Why do you put up with Sheldon?
Leonard: Oh, you know because we're friends.
Professor Proton: Why?
Leonard: Wow, you ask really hard questions. Look, I know he can be aggravating, but what you have to remember is he's not doing it on purpose, it's just how he is. But he's also loyal and trustworthy and we have fun together.
Professor Proton: You know you're describing a dog?
Leonard: He did bite me once. But in his defense, I came up behind him while he was eating.
Professor Proton: They hate that.
Leonard: Sheldon is the smartest person I have met. He's a little broken and he needs me. And I guess I need him too.
Professor Proton: Why is that?
Leonard: Boy, you will not let this go, will you?

Sheldon: I'm looking over my text correspondence with Beverly and I don't see anything that would have given her offense. Nothing's ambiguous, I spell everything out. Including "laugh out loud" and "what's the fracas?"

Amy: Are you really not gonna pick up your mother?
Leonard: No. It's fine, she likes to take a cab or a shuttle. That way she can meet people.
Amy: Well, that's kind of nice.
Leonard: Yeah, she always says that a stranger is just a person whose emotional weak point you haven't found yet.
Sheldon: Your mom is the best.

Leonard: How was your flight?
Beverly Hofstadter: There were some parents with a baby. A lot of crying.
Leonard: Well, babies do that.
Beverly Hofstadter: No, it was the parents. It seems they couldn't handle some constructive criticism.