My younger brother is 23, and he keeps talking about how he doesn't know what he's doing with his life.
I then him that I'm 30, and almost none of my peers "know what they're doing with their lives." We're all figuring it out--it's a crazy world. Perhaps not as simple (in some ways) as the one our parents came of age in.
There's a ton of time. My dad just started a whole new amazing chapter of his life at 55. Life is long. :)