Leonard: Even with your mother here, you are deliberately hogging all the attention from my mom. You're like one of those elephant seal pups that steals the milk from two mothers!
Sheldon: Do you mean what marine biologists refer to as "super weaning"?
Leonard: Yes, you are a super weaner!

Sheldon: Oh, good. You're here. I need your assistance.
Leonard: Can it wait until I put a Band-Aid on a goat bite?

Penny: Look, I'm not happy this happened, but I think I can get past it. I mean, we weren't engaged at the time, and it was just kissing.
Leonard: Right. Just kissing. It wasn't even very good. She was a smoker. I'd just been seasick...
Penny: Okay, that's enough. Stop talking.

Leonard: I have to get a lock for my door.

Sheldon: Well, I shouldn't be surprised. There's a rich history of brilliant minds descending into madness.
Penny: Come on, Sheldon. There are plenty of smart people who don't have mental problems.
Leonard: Yup, she's right. For every Newton who had a psychological issue, there's an Edison who was just a jerk. That could totally be you.

Leonard: You think they'll still go on the trip?
Sheldon: All I know is after the fight I went to Emily's to smooth-
Leonard: They're not going on the trip.
Penny: No.

Leonard: I'd love it if my dad could come.
Penny: Oh, you have to invite him. I haven't seen him since the divorce.
Leonard: Oh, he's like a different man. He stopped twitching, and I think he grew an inch and a half.

Penny: Do they know why the pipes burst?
Amy: They didn't say.
Leonard: Buildings that have a combination of copper and galvanized steel are susceptible to pinholes and corrosion caused by the mobility of ions in the water. Can't have your head shoved in a toilet as much as I did and not pick up a few things about plumbing.

Leonard: Never leave a belt on the floor. At night, they look like snakes.

Leonard: I would pull this car over and kick you out, but if Penny dumps me, you're all I got.

Penny: Well, it's like that science thing. For every action, you have a gigantic and annoying reaction.
Leonard: Just when I thought you couldn't get any hotter.

Penny: I'm not leaving you for Bill Gates.
Leonard: You sure? I bet his Internet's really fast.

Raj: Now it's happening to me. Ooh, I should probably make a list of all the scientific inaccuracies in Mamma Mia 2.
Penny: You're gonna go on live TV and admit you've seen that movie?
Raj: Hey, your husband's the one who took me.
Leonard: Meryl Streep and Cher? Yeah, I saw it.

Mrs. Fowler: Larry? I know you're in there!
Penny: Is that Amy's mom?
Mrs. Fowler: Let me in. (shouting) Let me in!
Leonard: Either that or the Big Bad Wolf.

Sheldon: This is an auspicious moment, like Robert Oppenhiemer or Neil Armstrong, we need the appropriate words to mark this historic scientific event.
Rajesh: How about, die toaster, die!
Leonard: That'll do it!