Leonard: Come on, Sheldon. You can't turn your back on physics. Besides, you have no idea what you're doing with this stuff.
Howard: But if you really want to learn the mechanical side, I can teach you anything you want to know.
Leonard: And instead of standing around watching, you can help us build your smaller guidance system.
Howard: And with all these new skills, you'd be able to fix any model train. You'd be the king of the train store!
Sheldon: Excuse me. I have a girlfriend. I'm already king of the train store.

Bert: Well, I really envy your relationship. Other than you two only having sex once a year, you're the perfect couple.

Amy: Actually, we met online. Our first date was at a coffee shop.
Sheldon: Although, unlike your date, she actually showed up. Oh, he looks sad again.

Amy: We should go say hi.
Sheldon: Why?
Amy: Because that's what you do when you see someone you know in a public place.
Sheldon: I have multiple restraining orders that say otherwise.
Amy: Sheldon, there's a difference between greeting a friend and following a celebrity into a bathroom.
Sheldon: If the judge couldn't explain it to me, I don't see how you will.

Howard: We're betting to see if Koothrappali can hold his breath longer than the disk can spin.
Sheldon: Its weight and smoothness, along with the slight concavity of the mirror, means it can spin for a long time.
Leonard: But Raj is from India, which means he's no slouch at holding his breath.

Penny: Okay, I want in. Ten bucks says I'll lose interest before that thing stops spinning.

Amy: Hey, Sheldon, I found a great restaurant for date night.
Sheldon: Kind of busy right now.
Amy: Oh, an Euler's Disk! Fun!
Howard: Yeah, we're seeing if Raj can hold his breath longer than it.
Amy: Oh. Immature.

Leonard: (To Raj) Dig deep! Like when we bet you couldn't fit into Howard's pants!

Raj: Oh, Daddy, you're so rich and funny.

Dr. Koothrappali: So what else is going on with your life?
Raj: Uh, well, I was dating a woman at the university, but we broke up.
Dr. Koothrappali: I'm sorry to hear that.
Raj: I know you are. That's why you just bought me a new iPad.

Raj: I can't believe what I'm hearing. This is deeply hurtful.
Dr. Koothrappali: You're also too sensitive. Women don't want that either.

Amy: The food here's supposed to be great. Don't fill up on chips.
Sheldon: Oh, I won't. I have a trick. I only eat equilateral triangles. Isosceles, isosceles, oh, scalene (breaks the corner off a chip and eats it) - You didn't see that.

Raj: It turns out he doesn't care if I'm married or if I'm single. He's basically given up on me.
Bernadette: Oh, I'm sure that's not true.
Raj: It is. He stopped trying to find Indian girls for me to marry.
Leonard: All you did was complain when he did that.
Penny: Leonard, he's hurting. Let him feel how he feels.
Raj: Thank you, Penny.
Penny: Yeah. Shoes, I'm a seven-and-a-half; boots, I'm an eight.

Penny: All right, how much exactly does he pay for?
Raj: Okay, I'll tell you, but please don't judge me. He pays for my car, my rent, and my credit cards.
Leonard: I'm trying, but I'm judging.

Amy: You know about that?
Bert: Uh, yeah, everyone at the university does.
Amy: Were you aware of this?
Sheldon: No. No, I only told Leonard, Howard, Raj, Kripke, uh, Professor Wu, Professor Klein, and a lunch lady in the cafeteria. How everyone else found out is a mystery to me.