Leonard: Well, I-I didn't quit. I said I was going to. I walked out the door and started crying. You know, "Oh, my, God, oh, my God, oh, my God, what'd I do?" And then he called me back in.
Penny: Then he changed his mind?
Leonard: He did not.
Penny: I'm really confused about how to react to this story.
Leonard: President Siebert didn't want to lose me. Even though they couldn't make me a lead investigator on a plasma team, there was an opening for a co-lead on a photon entanglement team. How cool is that?
Penny: You're gonna have to tell me.
Leonard: It's really cool.
Penny: Yay! Oh, I am so happy for you.
Leonard: I almost got what I wanted, and it never would have happened if you hadn't almost believed in me.

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.

Leonard: Penny, as a scientist, my job is to figure out why things happen. But I don't think I'll ever understand how someone like me could get to be with someone like you. You know maybe I don't need to understand it, I just need to be grateful. I love you, Penny.

Sheldon: This song is never going to stop. Have you ever dealt with something so relentlessly irritating?
Leonard: That's a trick question, right?

Amy: Wow. Déjà vu.
Sheldon: Amy, you're a neuroscientist. you know the latest research into déjà vu suggests it's nothing but the frontal regions of the brain attempting to correct an inaccurate memory.
Amy: You telling me stuff I already know is definitely déjà vu.

Sheldon: How can I tell if I'm doing something for a noble reason or a selfish reason?
Amy: Try saying the thing in your head and see if you can add the words, "That'll show 'em."

Sheldon: Leonard's about to demand a job that I don't think the university will give him. I'm worried he's making a giant mistake. But maybe I only think that because deep down I don't want him to succeed.
Amy: The fact that you're worried about your motivation supports the idea that you genuinely care for your friend.
Sheldon: I do. Thank you, Amy. You know what? After I've talked to Leonard, you've earned yourself a bonus lecture on Sponge Hulk.
Amy: That'll show me.