We are all not good at little to unfamiliar things that require skill. Also things that we don't see enough worthwhile benefit for if one does make an effort. So what the OP is really asking is what we are not good at that we've at least made an effort at. Note many of us are probably not good at things we tried and quickly realized further effort would be futile for the level we might pursue. Sports examples are golf, bowling, or shooting pool that I've played a little but never felt gaining skill had benefits for where my own life was going.
Well I''m quite ignorant of the kind of popular culture information people that watch Jeopardy or Trivial Pursuits are good at. Spent decades as an adult outside of sci-fi rarely watching all the historically popular TV shows of our generation. Oh, I've watched 5 minutes here and there of most TV comedies and dramas but rarely whole shows beyond my 20s. So yeah would score really bad on that show.
Also not familiar with most popular social card games outside of poker and blackjack.
My cooking is rather primitive. Have always had a poor attitude half jokingly expecting that would be something for my wife that due to circumstances never happened. Cooking is not something one can easily do in a residence that only has a stove top and microwave oven. I have no doubt that if I made an effort studying how to do so, that to reach a reasonable level would only require reading and experience.
I cannot understand science that requires a higher level of math than I've been exposed to. So will never understand quantum mechanics though I've certainly made an effort to reading Feynman and others. Likewise Faraday, Maxwell, Lorentz, Poincare, Einstein, Dirac and others work with higher levels of math that I long ago realized would be a wasted effort to pursue that requires starting at a time one is still in their teens.