President Siebert: Mrs. Latham, I'd like you to meet three of our outstanding young researchers. This is Dr. Leonard Hofstadter, Dr. Rajesh Koothrappali and Howard Wolowitz.
Mrs. Latham: Well, what happened to you, Wolowitz, couldn't stick with it long enough to get your PhD?
Howard: I'm an engineer. Most engineers don't bother with a PhD. But you may be interested to know I designed the zero-gravity waste-disposal system for NASA.
Mrs. Latham: Got it. You're a space plumber.

Penny: Good morning, slut!
Leonard: What?
Penny: Oh, please! I recognise the walk of shame when I see it. All you're missing is a little smeared mascara and a purse with panties wadded up in it!

Sheldon: Given how much time you spend engaging in pointless self-abuse, you might consider, just this once, using your genitalia to actually accomplish something.

Sheldon: An entire dinner to talk about your research? Where you going? The drive thru at Jack In The Box?