Mary Cooper: How was your flight?
Beverly Hofstadter: Very pleasant. And yours?
Mary Cooper: Lovely. Almost as if someone - not saying who - was watching over the plane.
Beverly Hofstadter: You're kidding, right?
Leonard: Subtle, mom, real subtle.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

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.

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?

Mary Cooper: When your mom gets back, I'm gonna need to apologize for the way I spoke to her.
Penny: Well, come on, she did kinda start it.
Mary Cooper: Doesn't matter. A good Christian would have turned the other cheek. On the other hand, a good Texan would have shot her, so I'll just split the difference.

Mary Cooper: Well, I would have to say when he was thirteen and he tried to build a nuclear reaction in the tool shed.
Sheldon: Ooh, this is a good one.
Mary Cooper: Now, the first thing you need to know about Shelly is, ever since he was a little boy, he was always concerned with the well-being of others. And he didn't think it was fair for people to pay for electricity, so he was gonna power the entire town for free.
Sheldon: Tell her about the uranium. Tell her about the uranium!
Mary Cooper: Oh, well! Well, this is adorable. When he arranged to get some yellow-cake from Chad, I thought he was talking about twinkies from one of his friends.
Sheldon: Yeah. But I wasn't, because I didn't have any friends.
Mary Cooper: No. It turns out this little scallywag was trying to use my Visa card to buy uranium from an African warlord in the country of Chad.

Raj: How old is this Jell-O?
Stuart: Well, it's carrots, so I'm gonna say very.