Just my general 2cents worth...
Vague goals aren't compelling enough to get you* going and the idea of achieving them may seem a little overwhelming. So you spend a lot of time in your head tying to sort it out.
Pick one thing that has interested you the longest and do something about it. Read up on it, take a course, join a club, go on a trip, volunteer, get a part-time job in it...just do something. It's the best way I know how to focus while getting closer to something that really matters to you. The more you do, the more you'll learn, the more you can dimensionalize your goals. And who knows, a new direction and new connections might emerge that you couldn't have predicted in the first place.
(* by you, I mean one--anyone)