I too have changed jobs and careers several times since graduating college. Strangely, doing so has actually been liberating for me. I entered a PhD program immediately after college, obsessed with not only being the greatest, but also the youngest. (I didn't just want to "break records," I also wanted to be many years younger than the previous record holder when I did.)
I let go of these fantasies the moment I dropped out of grad school though. I was starting over from scratch which meant I'd be too old to be the best and youngest at anything. And not chasing that goal has pretty much set me free. Everything is way more fun now, including being a complete noob in a room full of experts.
http://dilbertblog.typepad.com/the_dilbert_blog/2007/07/care... <-- I always appreciated this Scott Adams post. It helped me go from path #1 to path #2.
Ps. Your photos are phenomenal. Thanks for sharing, even though it was scary to! You are (almost certainly) already the top 25% at two or more things. Now how bout dat?! :D