I know a painter or two who automatically take very compelling photos without knowing a single thing about operating a camera or photographic theory. In many ways it's the same thing (doesn't apply to post-modern / abstract art).
At least a couple of the best, most famous photographers started life as painters. Bresson, Winogrand, to name a couple. Recreating by hand what you see in the world takes an incredible amount of observation. If you haven't done that exercise you should, it's been enlightening the few times I've dabbled in it. Start with a pencil and paper and just do a dirty sketch!
Disclaimer - I am neither a painter nor a photographer
Edit: in the last couple of weeks while I was on leave I watched this vid (
http://www.youtube.com/watch?v=OtcD84l9eUw) and that inspired me to go visit a bunch of art museums and study photos and paintings. It hasn't translated into visual skill yet lol but it has been a great experience.