Penny: You know, not a lot of people know this. But the monoamine oxidase enzyme was discovered by a woman, Mary Bernheim.
*Amy and Bernadette look puzzled by Penny's knowledge*
Penny: That's right, my phone is just as smart as you guys!

Sheldon: *knocks three times* Amy, Bernadette, Penny. *repeats three times*
Bernadette: He's never going to stop doing that, is he?
Amy: I don't mind. I'm hoping to put his love of repetition to good use someday.

Penny: Awkward silence, Sheldon on his phone, no touching; somebody's having date night.

Amy: It's actually steamier than it looks. Sheldon's looking up the phallic symbolism of root vegetables in renaissance paintings.
Sheldon: Oh no, I got bored of that. I'm just browsing cuticle scissors on Amazon.

Penny: How do you not tear off his clothes and take him right here on this table?
Sheldon: If you do that I'll scream.

Amy: I have some exciting news to tell you.
Sheldon: That makes two of us. My new cuticle scissors will be here in one to two business days. ... Come on, one.

Sheldon: You know, riding with Leonard has got a little tedious lately. The only car game he ever wants to play is the quiet game. And he's terrible at it, I always win.

Amy: To the Neil-mobile!

Penny: Hey, Princeton, look at that. Team community college-night school is in the lead!

Raj: In the last hour 162 people have read our profiles. How many of them have sent us messages?
Stuart: Combined?
Raj: Yes.
Stuart: Zero.

Stuart: I don't think I've ever felt so rejected. And I had a rescue dog that ran back to the pound!

Beverly Hofstadter: Hello, Leonard.
Leonard: Mom?
Beverly Hofstadter: I understand you have been whining about my parenting in order to emotionally manipulate your girlfriend.

Penny: Bernadette told me everything. Now you don't get the left or the right.

Beverly: Let's discuss why you continue to involve me in your sex life.
Leonard: Oh, please no mommy. No mommy.
Beverly: When you were six years old, you walked in on me and your father naked. I was swatting his bottom with your brand new ping-pong paddle.
Leonard: I didn't dream that!?
Beverly: How did that make you feel?

Stuart: Aw man, if I'd started this years ago I'd be divorced two or three times by now.