I don't exactly subscribe to "mind over matter", but mind over our own matter - that's different; that's real. The best people in the world I've discovered are not the ones with the positive attitude, or the most open perspective -- they are the people who never hold back yet always have something left within them to keep going. Live every day like this -- when the fatigue kicks in, that is not the end, THAT is the halfway point -- you can go twice the distance. And if you make it twice that distance, then that means you can go even further.

Note: yeah, I'm terrible company on a hiking and/or biking trip :)