I stumbled upon this photo of mine from 2006 that shows me in an accidental act of metaphor; ascending a steep incline but looking on to the next challenge. I've been told by several people many times that I push too far, too fast.
It's not that I consciously push myself against my own instincts that cry out for rest but that I am pushed by nature. It is an intrinsic property to who I am.
The urge is not unlike being hungry. It is ever-present and drives my actions -- pushing me harder, better, faster, stronger.