Howard: Now I rotate it horizontally on its center axis until the lights turn green.
Sheldon: Initiating rotation sequence. Don't look at me. Initiate.

Sheldon: You can't return it. Howard wiped his bottom with the warranty.
Raj: What?
Sheldon: I think metaphorically. But he was in the bathroom for a while.

Raj: It's like the best one they make, I just can't get it to work.
Howard: I'll figure it out.
Raj: It streams HD videos straight your phone when it's flying.
Howard: Nice. Where were you when I was single?

Bernadette: Well, now you get to go back as a successful scientist.
Amy: With a beautiful girl on your arm.
Sheldon: And a pointy hat sticking out of your eyeball.

Leonard: How'd you get ready so fast?
Penny: Oh, I packed light. Once I got through an entire spring break with nothing but a long T-shirt and a belt.
Leonard: Why'd you need a belt?
Penny: It's called an evening look.

Amy: I think it's really nice that you're sharing this experience with Penny.
Leonard: I thought it'd be fun to show her my old stomping grounds. I even know the exact spot where they used to stomp me.

Leonard: Now that we're all on the same page, let's get together tonight and work on it.
Sheldon: Get together tonight? Leonard, stop trying to control everything, and give poor Raj a chance to come up with what we should do. Go ahead, Raj.
Raj: Okay, I think we should do it right now.
Sheldon: Tonight works better for me.

Sheldon: So, often on the front of the locomotive is a large iron wedge for clearing objects off the tracks. Now, while commonly known as a cowcatcher, I prefer the more accurate "cow exploder."

Sheldon: Perhaps you'd prefer this one. The itzy-bitzy spider is not an insect at all. Because it has eight legs and two body parts.

Sheldon: Hey, would you like to hear some songs I've rewritten to get children interested in the hard sciences?
Howard: Sure.
Leonard: Really?
Howard: Yeah. I like music. I like science. I like making fun of Sheldon. Hit it!

Sheldon: *singing in the tune of "Bingo Was His Name-o"* There was a scientist who had a theory, and James Clerk Maxwell was his name-o. J-A-M-E-S, C-L-E-R-K, space, M-A-X-W-E-L-L, and James Clerk Maxwell was his name-o. There was a scientist who had a theory, and James Clerk Maxwell was his name-o. *claps* A-M-E-S--
Leonard: Okay, okay, we get it.

Penny: *using Sheldon's knock* Sheldon? Sheldon? Sheldon? *Sheldon answers with a suspicious and smiling look on his face*
Sheldon: I bet that started off as a joke, but by the third one, you realized there was something strangely enjoyable about it.
Penny: Yeah, I kind of wanna do it again.
Sheldon: I don't recommend it. You'll be doing it the rest of your life.

Howard: You don't think I'm a leader?
Bernadette: I was kidding. Of course you are.
Howard: Right. I couldn't change if I wanted to.
Bernadette: You better not change, because I love who you are. Now, will you need help cleaning all this up when you're done or can you do it all by yourself?
Howard: All by myself.
Bernadette: There's my big boss man.

Howard: Now if we're talking about being left out, you guys went to Skywalker Ranch without us.
Sheldon: Oh, I recommend that too. That was a magical experience.

Sheldon: Anyway, if you're looking for Leonard, he's with Koothrappali.
Penny: No, actually, I came to talk to you.
Sheldon: How nice!