I used to feel similarly for many years when I was younger. For the longest time I had just convinced myself that I was just different, that I did not want or need to be what most people consider to be happy, though I was not necessarily sad. I went on like that for a very long time before I met my wife. She started showing me a different side of life, a different way of looking at the world. I found something that I did not even know that I wanted. I suppose my point in all of this is life is not always so straightforward for everyone. Some people know what they want their life to be like right from the start. Other people have to discover what they want over time. It could sometimes take years, or it could come at you out of the blue one day unexpectedly.
I apologize if this does not really sound like an answer to your question. I am not always so great at finding the right words for my thoughts. Just know that there are plenty of people out there that can sympathize with you on that. That uncertainty is just part of life I suppose.