His memory has always been laughably impressive: https://www.youtube.com/watch?v=eNVJFRl6f6s
I’ve noticed a strong tendency toward eidetic memory in people that started in their professions without going to college. Very common in enlisted military, for instance. I think it might actually be quite natural. Education, I think, overloads a person with all of this useless stuff to make them ‘well-rounded’ and they lose their ability to focus on the details.
So trading one set of anecdotes for another: I don't see support for your hypothesis. I think it's plausible that professionally successful people without college education tend to have a better memory, perhaps because they need to in order to compensate for lack of formal education. But even that is unsubstantiated. We probably can't draw any meaningful inferences from the n = 1 example of one of the most successful basketball players of all time. Many of Lebron James' qualities - both mental and physical - are likely several sigma from the mean.