Well, since you asked...
I've always been a bit hyper, and find that I spend a lot of time running around in circles in my day to day life - both mentally and physically. I care about my work, and so I create a lot of stress for myself. I also find that it's stressful protecting my and my company's interests from those who would like to transfer whatever we've got to their own bank accounts!
So... When I'm hiking, life gets simple. It takes all I've got to make it up that slope, or make sure I'm not going to fall off that ledge, or slip on that wet log. If a big critter crosses my path, I don't have room in my brain to think about products and profit margins...! The sense of wonder inspired by a great view of a mountain pass, or of a heron in a swamp, or of a magnificent grove of old trees makes all the man-made problems I face seem so trivial.
I find that when I come back from a good hike, I'm much more centered and easy-going. I also look a heckuvalot better than I did before I started hiking!