My running was very simple; it was out of myself.
The athlete of today is not an athlete alone. He's the center of a team - doctors, scientists, coaches, agents and so on.
If I can get better, why not?
If you want to run, run a mile. If you want to experience a different life, run a marathon.
It's at the borders of pain and suffering that the men are separated from the boys.
Try for a goal that's reasonable, then gradually raise it.