Penny: What am I supposed to say?
Leonard: Say "Can't talk right now, hanging with my boyfriend. England sucks. You suck. USA number one."

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?

Sheldon: You may not realize it, but I have difficulty navigating certain aspects of daily life. You know, understanding sarcasm, feigning interest in others, not talking about trains as much as I want. It's exhausting!

Leonard: It's hard sometimes. Everywhere you go, guys hit on you, even if I'm standing right there. And they're all taller than me. Why is everyone taller than me? You know what, this is all in my head. It's my problem, not yours.
Penny: Leonard, why do you always do this? Listen to me, you're the one I'm with. You know I love you. So will you please relax, because you're driving me crazy.
Leonard: You know that's the first time you ever said you love me.
Penny: Yeah.
Leonard: We're just supposed to pretend it's not a big deal?
Penny: That's exactly what we're gonna do, because you're about to make me cry. And we both know if I start crying, you're gonna start crying.
Leonard: You're right, I should go.

Sheldon: (Playing hackey sack) One, two, three, four, five, six, seven, eight. Drat. I'm never going to get to forty-three again. One, two, three, four. Rats.