Amy: Do you think it's possible you might enjoy being on your own for a little while?
Sheldon: It's hard to say. I've never really lived by myself. What if I become strange and eccentric?
Amy: I'll love you no matter what.
Sheldon: Howard Hughes saved his urine in milk bottles.
Amy: We'll cross that bridge when we come to it.

Sheldon: Stuart, wait. I do know what it feels like to be left out.
Bert: I know how it feels, too.
Sheldon: All right, this is about me and him; you're not part of it.

Sheldon: Amy is free. She had a harp lesson on Saturday, but it got canceled. Boy, when you take an interest in people, you really uncork a geyser of nonsense.

Sheldon: So, have you and I returned to a social equilibrium?
Penny: Yes.
Sheldon: Great. New topic. Where are you in your menstrual cycle?
Penny: What?
Sheldon: I've been doing some research online, and apparently female primates, you know, uh, apes, chimpanzees, you, they find their mate more desirable when he's being courted by another female. Now, this effect is intensified when the rival female is secreting the pheromones associated with ovulation. Which brings me back to my question, where are you in (Penny slams door). Clearly, I'm 14 days too early.

Penny: And there was no-one there to take care of you?
Sheldon: No. No, my mum had to fly back to Texas to help my dad because the house had slipped off the cinder blocks again.
Penny: Again?
Sheldon: It was tornado season. And it was an aluminum house.

Leonard: Penny started taking a class. She wrote a paper, she didn't want me to read it, I went behind her back and I read it anyway.
Sheldon: Stephen Hawking hates me.
Leonard: I don't know what to do. I mean, the paper's terrible. But if I tell her, she'll know that I read it and she'll get really mad.
Sheldon: I was beating him so bad, he doesn't want to be friends anymore. Why does everyone love me except Stephen Hawking?
Leonard: Is it possible we're having two different conversations?
Sheldon: How would I know? I'm not listening to you.

Penny: Okay, well, anyways, I brought you a day-old cheesecake to cheer you up!
Sheldon: Stale pastry is hollow succor to a man who is bereft of ostrich.
Penny: Just say thank you.
Sheldon: I thought I just did.

Leonard: Come on. You can build things. You were an astronaut.
Howard: That's true. You know, as a kid, I used to make model rockets. That'd be pretty cool to do with a son.
Sheldon: Model rockets. Finally, something interesting! What is your preferred mode of recovery?
Amy: Sheldon, we're helping our friends.
Sheldon: And we got to model rockets, yeah? It was a tedious road, but well worth the effort.
Amy: So, have you thought of any names?
Sheldon: Amy, we finally got to model rockets. Why are you turning back?

Sheldon: You're a good teacher. Your son is going to be lucky to have you as a father.

Amy: What's going on?
Sheldon: What if there was something I wanted to do, but I was worried other people would think less of me?
Amy: Is that other person me, and does it happen in the bedroom, in which case I think I'm cool with it?
Sheldon: No. It's about working with Bert on - You know what? I'm not even gonna say it. I am just gonna say the letter it starts with and -"ology". G-- Oh, no, that's not gonna work.

Sheldon: And worse than that, Edison filmed the first on-screen kiss, so he's basically a pornographer. Although every time I put that in Wikipedia, someone takes it out.

Sheldon: I want a real wedding.
Amy: Well, Sheldon, it was just making us fight.
Sheldon: I know. But, Amy, I never thought I'd want to marry anyone. So the fact that I found you is astonishing. It's-it's like finding dark matter, except they're looking for dark matter. I wasn't even looking for you. S-So you're even better than dark matter.
Amy: (chuckles) Sheldon.
Sheldon: Plus, plus, you interact with light, so I can see you. And, also, you don't account for the missing mass in the universe. Oh, and-
Amy: Okay, I think you're getting caught up on the ways I'm not like dark matter.
Sheldon: Right. Sorry.

Sheldon: This isn't a desk. This is a Brobdingnagian monstrosity.
Raj: Is that the American idiom for giant, big-ass desk?
Sheldon: It's actually British.
Raj: Can you say it again for me?
Sheldon: Brobdingnagian.
Raj: One more time?
Sheldon: Brobdingnagian.
Raj: Now three times fast?
Sheldon: Brobdingnagian, Brobdingna-

Mary: Oh, Shelly. I wish your dad could see you now.
Sheldon: Me, too. I miss him.
Mary: He would be so proud of you. I know that I am.
Sheldon: Thank you. I mean, for everything. My whole life.
Mary: Oh. *Mary hugs Sheldon*

Amy: I can't believe you're taking this out on me. I was just trying to get publicity for our paper.
Sheldon: By making it seem like it was your idea?
Amy: I didn't write the headline, Sheldon. Did you even read the article? Because I talk about you continuously.
Sheldon: I know, and it just made you sound modest and charming.
Amy: Why can't you just be proud of me?
Sheldon: I am proud of you.
Amy: Really? Because you sound jealous.
Sheldon: Well, I'm that, too. I've seen Inside Out. I know I can feel two things at once.
[Bernadette fires at them]
Amy: Ow!
Sheldon: Ow! Well now I feel three things.