Almost had a highside last weekend. Avoiding it was 1% skill and 99% luck. I was just going too slowly for the bike to buck me off the saddle. Went into the corner at a timid speed too, so it wasn't even balls that almost did me in.
It can be argued that everyone has at least some amount of innate skill. You knew how to breathe when you were born, so there is some amount of skill there. Otherwise you would be dead; therefore skill ≠ 0.