"Straddling the top of the world, one foot in Tibet and the other in Nepal, I cleared the ice from my oxygen mask, hunched a shoulder against the wind, and stared absently at the vast sweep of earth below. I understood on some dim, detached level that it was a spectacular sight. I'd been fantasizing about this moment, and the release of emotion that would accompany it, for many months. But now that I was finally here, standing on the summit of Mount Everest, I just couldn't summon the energy to care," writes Jon Krakauer in his "Into Thin Air" account for Outside magazine, later speculating: "Reaching the top of Everest is supposed to trigger a surge of intense elation; against long odds, after all, I had just attained a goal I'd coveted since childhood. But the summit was really only the halfway point. Any impulse I might...