I’ll understand if you don’t take this question seriously; I realize it sounds kind of silly, but I promise that I would not waste your time with a frivolous question.
What I wonder is, how does a person know if he or she is stupid? It seems like the more a person knows, the more they realize they don’t know— and, conversely, with decreased knowledge comes a weaker sense of one’s limitations. For all I know, I could be a complete idiot, and never realize it because I’m too stupid to do so.
No need to apologize; it’s a good question and lets me bring in the Dunning-Kruger effect, which allows us to detect and kill replicants. Er, which tells us that while competent people are pretty good at estimating how competent they are, incompetent people wildly overestimate their skills. E.g. in tests of four skills, those scoring in the bottom quartile (thus, averaging at the 12.5 percentile) estimated that they were in the 62nd percentile (i.e. well above average).
So the bad news is, yes, if you’re stupid you probably don’t know it. But then the good news is, if you really wonder, you’re probably not.
I suspect you know how well you do on tests and your job. I was always one of the top kids in my class, through high school; then I went to a good university where everyone was smart, and that cured me of any worries that I was a genius. For what the real geniuses are like, I recommend Richard Feynman’s memoir, “Surely You’re Joking, Mr. Feynman”. Not only is it fun to read, it shows how a smart person approaches the world, and shows how he compared himself to even smarter people, such as Niels Bohr and Einstein.
To some extent, intelligence isn’t even the main thing. As momentum is mass times velocity, I think great minds have a quality that’s used with intelligence and multiplies it. Or several different qualities. Some people just have so much energy that they can crack a problem by direct hard work. Some are particularly gifted at finding lateral solutions. Some partner with someone else whose strengths and limitations complement theirs. So even if you conclude that you’re no genius, that doesn’t necessarily mean you’re limited.