Leonard: I'm done enabling him. Like, this is his spot and-and the thermostat has to be set to his comfort level, even though he doesn't even live here anymore and I'm always chilly.
Raj: Is that why you wear a hoodie all the time?
Leonard: Why would-- Yes! To accommodate Sheldon! And what-what about this-this thing? Why is it here? I'll tell you why. Because it was here when I moved in, and, for no earthly reason, he forbade me to touch it.
Amy: Well, if you don't like it, get rid of it. Put it in the closet.
Leonard: You know what, I will. [Leonard tries to move the helix structure. Lots of little beads fall off and come crashing to the floor]
Raj: I bet that's the reason.

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.

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: 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.

Amy: Oh. That's me. Hello? Yes, this is Dr. Fowler. I see. Okay, thank you. We won.
Penny: Congratulations!
Leonard: Oh, my God!
Sheldon: We did it.
Amy: I know. Can you believe it?
Sheldon: That's a good point. What if I'm dreaming? [Leonard slaps Sheldon] We won the Nobel Prize!

Penny: So, I guess the only thing that actually stays the same is that things are always changing.
Sheldon: Interesting. So you're saying the inevitability of change might be a universal constant.
Penny: Well, there's a little more to it than that, but, yeah, sure.

Penny: Well should we wake him up?
Leonard: Well, he did say if he fell asleep, we were allowed to slap him awake.
Penny: Oh, boy.
Leonard: Wait a minute. Why do you get to do it?
Penny: 'Cause I called it.
Leonard: Well, you can't just call it. You have to earn it.
Penny: Oh, and you've earned it?
Leonard: No one has earned it more than me. [Amy clears her throat] You have your whole life to smack him around. This is my time.