Sheldon: I cannot wait to sleep in my own bed.
George: You didn't tell him on the plane?
Sheldon: Tell me what?
Mary: I thought you were gonna tell him in the car.
George: Well, he was grumpy in the car.
Mary: How do you think he was on the plane?

Sheldon: Regardless, I'm not interested in making any more friends.
Mary: Oh, I don't think that's how you really feel.
Sheldon: It is. From now on, it's a hermit's life for me.
Mary: I bet, when you grow up, you will be surrounded by lots of smart, wonderful friends.
Sheldon: I can't see that happening.

Sheldon: Mom, when should I be expecting my testicles?
Woman: [turns around] What is wrong with him?
Mary: Nothing is wrong with him. Now turn around before I knock your lights out.
Sheldon: Hello.

Sheldon: And then they laughed at me for not knowing something that they knew. Who does that?
Mary: You do.
Sheldon: Well, this is no time for a teachable moment. Your child is hurting.
Mary: Sorry. [taps Sheldon's shoulder] There, there.
Sheldon: I guess that'll do. Now, how about a hot beverage?

Mary: Are you ready for your surprise?
George: I sure am.
Mary: Okay. [German accent] Hello, you handsome American boy toy. I am Helga. Do you like what you see?
George: [German accent] Yeah. Yeah. Yeah. Yeah. [both laugh]
[Sheldon unlocks the front door and walks into the house]
Sheldon: Hello?
Mary: [o.s.] Are you sure your wife won't come home?
George: [o.s.] [laughs] I'm sure.
[Sheldon knocks on his parents' bedroom door and then opens it]
George: [o.s.] Yeah, yeah. [Mary laughs] Oh, Helga.
Adult Sheldon: I never talked to my father about what I saw that day, but, from then on, I added extra knocks so people could get their pants on.

Sheldon: Mark my words, string theory is going to be the next big thing.
Mary: What does it do?
Sheldon: It explains the fundamental forces of the universe. How everything works, where everything came from.
Mary: I know where it all came from. [points to the heavens]
Sheldon: Mother, we're in the sky. Why are you pointing up?

Pilot: [v.o.] Sorry for the delay. We hope to be wheels up in about 20 minutes.
Sheldon: That's what he said 20 minutes ago.
Mary: Nothing we can do.
Sheldon: If we don't take off soon, we'll miss our connecting flight to Houston.
Mary: It's out of our hands. I'd tell you whose hands it's in, but you don't like that.