You eventually find out what you really want to do. Then you learn more skills, and you learn more who you are, and you see more possibilities, and then you learn what you really wanted to do. And then you learn more...

I'm 53. I'd say that I learned what I really wanted to do only in the last 3 to 5 years. But I may be mistaken; I may not yet know what I really want to do.

It's probably not just one thing for your whole life.