CineFix sums up Keanu Reeves in The Matrix hilariously: he gets his ass kicked, learns to kick ass and then promptly kicks everyone's ass. The problem that you maybe didn't know? Keanu actually couldn't kick in the movie's epic fight scenes.
He had spinal surgery before filming which prevented him from kicking so fight scenes had to be re-choreographed to downplay Neo's kicking. Other factoids include S&M night clubs, twins, real stunts and saving money.