Guardian has a nice article about peak performers.
How much of it is pure genius, how much of it is hard work?
The article finds a common theme - 10000 hours of practice required for all world class work.
In my view, you have to be a real genius, superbly motivated, and genuinely hard working to be able to put enough hours.
So, "10000 hours" may be more like an effect, rather than cause, of the genius.
The truth might be simpler - peak performers keep trying until they get successful.
