Only two things are infinite, the universe and human stupidity, and I'm not sure about the former.
A fool sees not the same tree that a wise man sees.
WILLIAM BLAKE, The Marriage of Heaven and Hell
Buffoons, buffoons! One can play any tune on them!
LUIGI PIRANDELLO, Henry IV
Stupid was a prison they never let you out of, no time off for good behavior, you were in for life.
STEPHEN KING (as Richard Bachman), Blaze
Smart people don't have the luxury of playing stupid.
DAN BROWN, Deception Point
Life is hard, but it's harder if you're stupid.
Who's the more foolish: the fool, or the fool who follows him?