When I was younger I wanted to be an astronomer, because nothing excited me more than looking at the stars and the whole universe in front of me to discover. Then I realized that required exceptional qualifications in mathematics, and all that math did not make me nearly as happy as looking at the sky above me did. Granted my biggest dream is still to be an original Mars colonist, but it's unlikely I can get in on that, even within my lifetime.
So now I'm debating on whether to become a professor or a forensic anthropologist/forensic pathologist; the later two are not for the squeamish, but I've never been that way, and if anything, curious about the process of death so it seems like a good paying niche career I'd enjoy.