I grew up watching my big brother (actual big brother, not some Simpsons awesome guy) play games. Strange thing is that years later I'll still sit down and watch him play games, but can't really stand to watch anyone else do it.
I've noticed reciently that it's because he and I play games in the same way. (ie. move in the same way around the world and so on.) I think I was just so influenced by watching him play that I naturally picked up his playing style!