What You'll Wish You'd Known

Gwen linked to Paul Graham's graduation speech, which he unfortunately never delivered. It's more honest and realistic than most talks about finding your path in life (although not as gritty as Dave Pollard's undelivered commencement speech). His general advice relating to high school and self-actualization seems to be to jump through the hoops and spend as much time as you can pursuing interesting questions and projects:

"And what's your real job supposed to be? Unless you're Mozart, your first task is to figure that out. What are the great things to work on? Where are the imaginative people? And most importantly, what are you interested in? The word 'aptitude' is misleading, because it implies something innate. The most powerful sort of aptitude is a consuming interest in some question, and such interests are often acquired tastes."

It's all about taking responsibility for your life, rather than deferring responsibility to your school, employer, parents or peers. I suppose it would probably still sound preachy to any teenager, but I think it's closer to the truth than most advice about figuring out your future. It's really worth reading the entire thing.