Leonard: It's not that I'd stopped trying, it's just how relationships progress. They start with infatuation, but over time mellow into something more comfortable.
Sheldon: Hmm. Yeah, you're right. It's like when I first encountered the Pythagorean Theorem. You know, I was blown away that the square of the hypotenuse was the sum of the squares of the opposite sides. Yeah, but now I'm just like "eh."

Penny: It's not that I want to go, I just think it'll make Leonard happy. And if I have to watch him squeeze into an Ewok costume, so be it.
Amy: Look at you, going to Comic-Con, talking about Ewoks. I really have become the cool one around here.

Amy: Look, we can't just throw away Penny's stuff, but we can ask if she wants any of it back.
Sheldon: You know, I wonder how she feels about all this artwork.
Amy: Well, I'm sure she misses this one. I mean, it's the greatest gift I've ever given anybody.
Sheldon: It truly does capture the beauty of your friendship with Penny.
Amy: It may have appreciated in value. The artist killed himself shortly after painting that.

Bernadette: It's okay, I'm just being emotional about this. Can you not tell Howard?
Stuart: Well, don't you think it'd be healthier if you told him what's going on with you?
Bernadette: Don't you think it'd be healthier if you had your own apartment, grown man?
Stuart: Your secret is safe with me.

Amy: Wait, are you saying if we combine my experiment with your calculations, we can determine the precise moment in time when the wave function collapses?
Sheldon: It could be the most inspired combination since I mixed red Icee into my blue Icee. It was like drinking 2/7ths of the rainbow.
Amy: Sheldon, this is really interesting.
Sheldon: Yeah and this one won't stain my teeth purple.

Sheldon: And you realize what the next step is?
Amy: Set up a second culture and try to replicate our results.
Sheldon: Uh, no. We lock that door, lower our underpants a little, and make a baby.

Penny: Does the baby have a name yet?
Howard: We have named her Halley.
Penny: Oh!
Leonard: Oh, like Halley's comet.
Howard: Exactly. Also like the comet, Bernadette said she's not gonna have sex with me for another 75 years.

Bert: Okay, well, thanks for coming by. You're nice people.
Penny: Well, so are you. In fact, you know what? We will never take you for granite. Did you get that? Granite? A little geology joke.

Howard: Stuart, stop driving like an old man. Speed it up a little.
Stuart: I'm not an old man! I just can't see at night.

Raj: Hey, this pregnancy had an emotionally-needy third wheel way before you came along.

Bernadette: But I thought I'd be more excited.
Dr. Koothrappali: Oh, being excited isn't a guarantee of anything. Rajesh's mother was thrilled when she was pregnant with him. After he was born, she doted on his every move. And you know what happened? He broke her heart, moved halfway around the world, and dates only poor white women. So you never know.

Amy: How can he not remember a day?
Penny: Well, people who are abducted by aliens lose time. I mean, maybe it happens to the aliens, too.

Sheldon: No matter where I am, this will always be my spot.

Penny: You can stay in Leonard's room, and we'll stay at my place.
Amy: You're sure that's not an inconvenience?
Penny: No, not at all.
Leonard: And we live with Sheldon, so the word "inconvenience" has really lost all meaning.

Sheldon: Two years ago I got my driver's license.
Amy: What? Why didn't you say anything?!
Sheldon: I like being chauffeured around. It makes me feel important.
Amy: So when I got up at 4:00 AM to drive you across the desert to an antique train museum, I didn't have to?
Sheldon: No, you didn't. But keep in mind, I felt extremely important.