There are no shortages of people in these threads who genuinely believe that Neumann was supremely intelligent, beyond the conception of regular people. I'm sure you'll find them. It's not even unique to Neumann.
Nothing. They put effort into his education because of his brilliancy, and your standard Jewish-American household could do the same thing.
People can recall pages from books if they put the effort, and regular people routinely do - an average person can memorize thousands of pages. Again it's that he could do it faster that's exceptional.
And they would be right. This sort of genius is not only nurture and hard work, but nature as well. Like no matter what I do in my life, I will never even approach that level.
Of course he is still human, and someone will born (rarely though) that will achieve similar feats, but let’s be honest and just say that what he did is well beyond the reach of the average people.
Beyond that, yes he was incredibly accomplished, very prolific, and supremely intelligent, but it is important to remember that he was still human and not some kind of transcendant being outside of earthly considerations.