“- Dr. Lilian Thurman: Do you still think about girls a lot? How are things going at school?
- Donnie Darko: I think about girls a lot.
- Dr. Lilian Thurman: I asked you about school, Donnie.
- Donnie Darko: I think about fucking a lot during school.”
Katharine Ross - Dr. Lilian Thurman
Jake Gyllenhaal - Donnie Darko

- Erica Sutton: If I told you, "Don't think about the color red", what would you think about?
- Matt: Sex.
Shannyn Sossamon - Erica Sutton
Josh Hartnett - Matt

“Imagine how many people out there are fuckin' right now man, just goin' at it.”
Rory Cochrane - Slater

“- Hedley Lamarr: Think of your secretary...
[the pen goes straight in]
- Governor William J. Le Petomane: Thank you. That's a good one.”

Mel Brooks - Hedley Lamarr
Mel Brooks - Governor William J. Le Petomane

“- Betty Childs: Are all nerds as good as you?
- Lewis: Yes.
- Betty Childs: How come?
- Lewis: 'Cause all jocks ever think about is sports, all we ever think about is sex.”

Julia Montgomery - Betty Childs
Robert Carradine - Lewis