Jackie Coogan's stand-in
One of the funniest movies ever made. Everyone who loves it has their fave moments. And sometimes it's hard to choose a fave moment. My fave is during the fight between Russ Tamblyn and Jackie Coogan. Watch carefully when they make the cut to the "body flip." Freeze the frame if you have to, but look at the poor dishelved, old, thinner Mr. A stand-in. He looks like some bum off the street. And listen to his pathetic grunt of pain when he's flipped onto the cement floor. You'll roll with laughter.
There is no "off" position on the genius switch.