" In the hardest moments of a long race, the athlete’s entire conscious experience of reality boils down to a desire to continue pitted against a desire to quit. Nothing else remains. The athlete is no longer a student or a teacher or a salesman. He is no longer a son or a father or a husband. He has no social roles or human connections whatsoever. He is utterly alone. He no longer has any possessions. There is no yesterday and no tomorrow, only now. The agony of extreme endurance fatigue crowds out every thought and feeling except one: the goal of reaching the finish line. The sensations within the body – burning lungs, screaming muscles, whole-body enervation – exist only as the substance of the desire to quit. What little of the external environment the athlete is aware of – the road ahead, the competitor behind, the urgings of onlookers – exists only as the substance of the desire to continue. The desire to continue versus the desire to quit – the athlete is this and this alone until he chooses one or the other. And when the choice is made he briefly becomes either persevering or quitting until, after he has stopped at the finish line or, God forbid, short of it, the stripped-away layers are piled back on and he becomes his old self again. Only not quite. He is changed, for better or worse. "
― Matt Fitzgerald , Iron War: Dave Scott, Mark Allen, & the Greatest Race Ever Run