It depends on how you define "watching a movie" too. For me, I don't always sit down and stare at the screen when watching a loved film. You put it on and enjoy it while you do other stuff. That's certainly why my "viewing count" is high on certain films. I have seen BTTF hundreds of times, but I've only sat and watched it a dozen times.
500 for sitting and staring does seem like a lot.