I think that we are always learning as we ride, sometimes we may not even realize it.
I've been riding since I was a kid, but would still like to do dirt camp and a superbike school.
I think there are VERY few people below the level of a pro racer than wouldn't benefit from one of these schools.
We all do dumb shit sometimes and fall down tho. I would say that doing dumb shit is the leading cause of most single bike accidents.