Leonard: There has got to be a right decision based on empirical evidence. Look, I made pros and cons lists, and then I came up with three different scoring systems to determine the best project. I just don't know what scoring system to use. So I'm working on a meta-scoring system to score the scoring systems, but the math is really complicated. You want me to walk you through it?

Sheldon: I remember the song! It's called "Darlin'" by the Beach Boys! Oh, thank goodness! I'm not crazy! I don't have to take a pigeon as my bride!
Leonard: There goes our shot at him living on the roof.

Howard: Don't feel bad. Some day someone will be throwing out your work, too.
Leonard: That someone was Sheldon and the day was yesterday.

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?

President Siebert: So, there are some funds left in the general administrative grant, and I need somebody to decide how we should disburse them.
Leonard: Really? Wow, what an honor. Thank you. So how do I decide who gets the money?
President Siebert: How do you decide anything? Think about it with your brain, and then say it with your mouth.

Sheldon: All right, I've kept you in suspense long enough. "Dutch" is a bastardization of the word "Deutsch," meaning German.
Penny: What's German for "annoying"?
Sheldon: Nervig. Why do you ask?

Sheldon: This reminds me of a traditional Amish barn raising. With everyone pitching in.
Howard: How exactly are you pitching in?
Sheldon: I don't hear anyone else giving facts about traditional Amish barn raising.
Leonard: The rest of us are pitching in with hammers and nails.
Sheldon: Well, facts are my nails, and my voice is the hammer which pounds them through the wood of your skull.
Penny: Well, that is how it feels.