Just thinking out loud here. I feel most alive when I'm in pain. Specifically, the pain I feel when I'm pushing myself hard at work or at play riding my MTB. I hate the modern day world of going from one box to another with a box on wheels. In a temperature controlled environment that's making us weak. Get outside, smell the roses and live a little...Rant over 
Man, up-hill is a B! I enjoy MTB only when it's downhill lol.
Haha yeah it's only worth it if the descent is righteous. My local trails here in east county SD are bitchin!
Lucky!