Ah, a Spaceballs quoting thread. Every webboard needs one of those.
So, here's the ever popular...
DK: What the hell am I looking at? When does this happen in the movie?
CS: Now. You're looking at Now, sir. Everything that happens now is happening Now.
DK: What happened to Then?
CS: We past that.
CS: Just now. We're at Now, now.
DK: Go back to then.
CS: We can't!
CS: We missed it.
CS: Just now!
DK: ...when will Then be Now?