Once you turn eighteen, you should at least have a vague understanding of how this works, and that's the biggest clue if you still haven't figured it all out. If by now, you haven't figured out what this particular "skill" is, then maybe you live under a rock or something. There should be a game show where you are pitted against other people doing something that is universally known so that you could really measure up your skill on that.
But what if people competed about something that they all know how to do, but have different levels of skills per person? No, this isn't about a particular sport or playing a particular musical instrument, as not all people know how to do these things. You can't really expect the average person to know all those things, that's why it's common for people who watch these shows laugh and facepalm themselves, especially if they know the answer and the contestant on the show does not. Some of these shows require you to be knowledgeable in various facts about the world like what is the capital city of this particular country or what characteristics does this particular animal has.
The motivation to push the contestants to do their best is obviously there, but sometimes, it isn't as fun to watch given that not all contestants have what it takes to win. Most, if not all of these game shows offer tangible prizes like cash, cars, and even properties. With all the game shows available on TV, it's hard for you to find one that you would really enjoy.