I'm mapping basic topics of conversation and with whom they can be discussed. I've called these circles zones of privacy. Don't google that unless you want to see pictures of people's genitals.

Sheldon

Dr. Koothrappali: You're an adult who can't get by without an allowance from his parents. Women don't want that.
Raj: What are you saying? That you're giving up on me? What kind of father gives up on his son?
Dr. Koothrappali: I have six children, five of whom are married and self sufficient. I don't think I'm the problem.

I really envy your relationship. Other than you two only having sex once a year, you're the perfect couple.

Bert

Amy: Our first date was at a coffee shop.
Sheldon: Although unlike you're date, she actually showed up. [pause] Oh, he looks sad again.

Stuart, don't you drink my milk!

Bernadette

Leonard, in the world of theoretical physics, you never finish. So much is unprovable. But when I was studying that railway guide, it was so tangible and so satisfying that something just clicked. Then it clacked. Then it clicked, then it clacked. Click, clack, and clickity clack, and here we are, woo woo!

Sheldon

Howard: How'd you even get that up the stairs?
Sheldon: I said to myself, I think I can, I think I can. And then I couldn't.

Penny: Alright, you guys ready to get crazy?
Amy: Well, the bra under here ain't beige.

Amy: Is there anything we can do?
Bernadette: Sure. Open up a college fund, shop for life insurance, and in the laundry room there's a mountain of dirty laundry. Wash it or burn it. Your choice.

This doesn't happen very often, but here comes a hug. [pause] Oh dear, I have to tinkle again.

Sheldon

Leonard: So, you're gonna throw me under the bus?
Penny: I'm gonna throw you so hard, I'll probably win a stuffed animal.

Penny: How is this any different than you making me live with Sheldon?!
Sheldon: Hey, I shared my Honey Nut Cheerios with you!

TBBT Quotes

Oh, Bernadette, please play my clarinet.

Raj's poem

Sheldon: I'll have a diet Coke.
Penny: Can you please order a cocktail? I need to practice mixing drinks.
Sheldon: Fine... I'll have a virgin Cuba Libre.
Penny: That's... rum and Coke without the rum.
Sheldon: Yes, and would you make it diet?