I don't know if people are mediocre, I think everyone has a talent in one direction. I think people are dishonest about what they are and present themselves in a way to best fit in.
Life your life and say 'I don't know' when applicable. You might only need to say it once if you are open to learning
that little aphorism about "the older you get the more you realize how little you know" is true and will hit you like a brick wall. despite what society says "I don't know" is an excellent response to any question. this should be followed up by "but I will find out". that's what's important.