You seem quite confident about declaring what everyone else is or isn't capable of, which is interesting coming from someone who was not successful themselves.Real mathematicians get started young, like ten years old, and have a sort of obsession with it. You can't compete with these people, who may have been at your present level when they were twelve years old.
I can't do any of them at all. One of my professors could do about a third of the problems. But a few students get a perfect score.
You have no hope with the Putnam.
I was never able to understand the Riemann Hypothesis. I once picked up a graduate level book on it and wasn't able to make it past the first page
The best you can hope for is teaching math in a junior college or high school.