Have you ever noticed that anybody driving slower than you is an idiot, and anyone going faster than you is a maniac?
I love insane, stupid comedy, but I can only make it work if it's a character I can give some history to and make real. Like the guy I played in 'Little Miss Sunshine.' He's a maniac, but to me he was absolutely believable.
The irrational in the human has something about it altogether repulsive and terrible, as we see in the maniac, the miser, the drunkard or the ape.
There was a reason my first substantial role after rehab was to play a maniac whose personal story ended badly. I knew what it was like to go those dark places. I played a guy who died as a result of his abuse.
Have you ever noticed? Anybody going slower than you is an idiot, and anyone going faster than you is a maniac.