Amy: You can't blame yourself. When your pre-frontal cortex fails to make you happy, promiscuity rewards you with the needed flood of Dopamine. We neurobiologists refer to it as the skank reflex.

Amy: Okay, what is going on?
Penny: We just want you to be prepared for any surprises that could happen tomorrow.
Amy: What surprises?
Bernadette: We don't want to spoil anything, but you should know that Sheldon said he's ready to be physical.
Amy: You shut your damn mouth! You actually heard him say this?
Penny: Yes, he said he wants to do something to show you how much you mean to him.
Amy: I can't believe it. I don't know what to say.
Bernadette: Well, we're really happy for you and we know how much-
Amy: I do know what to say. Let's get me waxed!

Sheldon: Sheldon Cooper does not get lucky.
Amy: You and me both, brother.

Amy: Do you have any idea how hard it is to laugh at a knock knock joke that starts "Knock Knock Knock, Amy. Knock Knock Knock, Amy. Knock Knock Knock, Amy"?

Leonard: Well, uh, okay, um, I dont want to get back together with Penny. We tried it, it was crazy, it didn't work, but I can't deal with the fact that she slept with my friend Raj. And then I find out that Raj's sister Priya, who I've been going out with for eight months, is moving back to India. So I'm just completely confused and alone.
Beverly Hofstadter: I understand.
Leonard: Got any advice?
Beverly Hofstadter: Yes. Buck up.
Leonard: Excuse me. You're a world-renowned expert in parenting and child development, and all you've got is buck up?
Beverly Hofstadter: Sorry. Buck up, sissy pants.

Sheldon: For the record, I do have genitals. They're functional and aesthetically pleasing.

Amy: A guest in my trundle bed and a boy at my door. I wish I could tell thirteen-year-old me it does get better.