What is genius? Genius is characterized by highly divergent thought, especially as compared with conventional wisdom. From this base notion of divergence, you actually get either genius or insanity.

Genius is characterized by divergent thought that feeds back with the external environment (society, historic events, etc.)

Insanity is characterized by this same divergent thought with the feedback being self-referential only. Thus it isn’t grounded in any way that society recognizes.

With that, neither genius nor insanity requires anything other than a highly divergent thought process marked by a level of attachment or detachment to society.

I know, they're bloody insufferable and impossible to teach. Best, is let them get demotivated and turn to drugs and crime: then we get evil geniuses who can't learn.

Teaching however can supress genius.

Many things can suppress genius. It's not actually a very reliable trait.

It occurs in most of us, though for far shorter than it should. If flashes of genius are rewarded they can grow, but mostly, harsh reality stifles the optimistic hope at it's root.

Genius here: was there anyone suggesting that it could be?

Well I don't generally consider chess mastery to be a sign of genius. Or maths, or music either. Fundamentally they are not creative, generative activities. There's a reason they are called a prodigy and not a genius. Of course there are the rare genius composer (eg Mozart) or mathematician (eg Euler).

I consider mastery of anything to be a sign of genius. Someone out there is in the top .001% of skill for underwater basketweaving, and I think they're a genius in that category.

Mathematics is a creative activity, at least at the professional level.

If he wanted to prove his thesis, he should have adopted.

The famous book: https://en.wikipedia.org/wiki/How_to_Solve_It

You tell me. You’re the genius.