Every success proves nothing. It can be luck, it can be accident, it can be smarts… you can’t be sure.
I am an architect by trade… and all my life as an architect I was wondering if I was talented. I could never say for certain. I could win contests, I could win awards, talent is not proven by them.
Finally I gave it up and sighed a sigh of freedom and relief.
You are the same way about being smart… or whatever is your issue. (Some people have an issue with being liked, loved, valued, respected, etc. But I think everyone has some issue with smarts. I could be wrong…)
My recommendation is that you consider the Forrest Gump saying: Stup