From "The Philosophy of Andy Warhol (From A to B and Back Again)", Andy Warhol, 1975:
I always like to work on leftovers, doing the leftover things. Things that were discarded, that everybody knew were no good, I always though had a great potential to be funny. It was like recycling work. I always thought there was a lot of humor in leftovers. When I see an old Esther Williams movie and a hundred girls are jumping off their swings, I think of what the auditions must have been like and about all the takes where maybe one girl didn't have the nerve to jump when she was supposed to, and I think about her left over on the swing. So that take of the scene was a leftover on the editing-room floor -- and out-take -- and the girl was probably a leftover at that point -- she was probably fired -- so the whole scene is much funnier than the real scene where everything went right, and the girl who didn't jump is the star of the out-take.
I'm not saying that popular taste is bad so that what's left over from the bad taste is good: I'm saying that what's left over is probably bad, but if you can take it and make it good or at least interesting, then you're not wasting as much as you would otherwise. You're recycling work and you're recycling people, and you're running your business as a byproduct of other businesses.... So that's a very economical operating procedure. It's also the funniest operating procedure because, as I said, leftovers are inherently funny.
from my recent show of art made from junk on the street -- I agree, leftovers are funny!