Sheldon: Hello, I'm Dr. Sheldon Cooper.
Amy: And I'm Dr. Amy Farrah Fowler.
Sheldon: Based on the glowing reception of our recent Behind the Flags retrospective, we thought you might like to see how it all came together.
Amy: So welcome to tonight's episode,
Both: Fun with Flags - Behind the "Behind the Flags: A Retrospective" Retrospective.

Zack: Do you have a bodyguard to keep spies away?
Leonard: I have Sheldon, that keeps most people away.
Zack: I miss that guy. He's like the Swedish Chef Muppet. I don't know what he's saying, but he's funny.
Leonard: Oh, I know what he's saying, and he's not, he's not funny.

Bernadette: So you wanted to learn something physical and you came to Howard Wolowitz?
Howard: Hey, the circus arts are very physically and mentally demanding. Have you ever tried to juggle?
Bernadette: Yes, I'm juggling my love for you and my embarrassment of you right now.
Howard: And it's hard, isn't it?

Wyatt: Welcome to the family, Leonard. Don't lend your new brother-in-law money.

Leonard: So, Rebecca, how did you become a personal trainer?
Rebecca: I came to Los Angeles to be an actress, and things didn't really work out.
Sheldon: I'd say she's copying you again, but I'm getting tired of sitting in the hall.

Sheldon: Okay, quick question. Am I allowed to exchange pleasantries upon meeting this colonel?
Leonard: Yes.
Sheldon: Am I allowed to inform him that Colonel Sanders was never actually in the military?
Leonard: I'm getting enraged.

Sheldon: Shall we?
Raj: Oh, my God. It's light, it's flaky, it's buttery. You don't need to have sex with him, just eat one of these.

Raj: So how did you two meet?
Rebecca: Oh, it's such a cute story! We met on a dating Web site.
(silence)
Leonard: Is that it?
Rebecca: Oh, sorry. The end.

Sheldon: What happened to me? I used to excel at these things.
Howard: Kids are always better at video games.
Sheldon: Well, I don't like it.
Leonard: If it makes you feel better, you still dress like a child.

Penny: Hey, you ready to go?
Leonard: Yeah, I guess.
Penny: What's the matter?
Leonard: Honestly? It's a little strange having dinner with your ex-boyfriend, and it's not like we have a lot to talk about.
Penny: What? He loves you, okay? And he's interested in your work. You could talk about the infinite perspective -- I swear I know it.

Leonard: Where did you go to school?
Colonel Williams: MIT.
Howard: Well, hey, me, too.
Colonel Williams: I should have known. Behind every great invention is an MIT mind.
(Sheldon gasps, but controls himself)

Raj: If you really want to challenge yourself, you could learn to speak Hindi.
Sheldon: Jab mein aat saal ka tha Maine seekha tha.
Raj: Could you say that in English? I actually, I never learned Hindi.

Bernadette: When I go back to work, we're gonna leave her with these people. We don't know anything about them.
Howard: They're highly-trained educators with background checks. They're even required to be current on all vaccinations.
Stuart: You leave her with me, and I'm not any of those things.

Zack: So, Penny, what's going on with you? How's the job?
Penny: Uh, it's okay, I'm still in pharmaceutical sales.
Leonard: She's doing amazing. She can actually make a side effect, like 10% chance of liver failure, sound like a 90% chance of liver success.

Colonel Williams: All you need to worry about is, right now, it's (wide gesture) this big, and we need it to be (small gesture) this big.
Leonard: That's a lot less big.
Colonel Williams: Yes, it's (wide gesture) this much less big.