I hear the bell

Weariness.  Bone aching, drained of energy to do the next thing, even it's just going to the bathroom.  Fortunately, the thing, that thing that has knocked me on my ass, eventually loses its power to terrify me.  It either becomes the new reality, or it goes away, most often slipping quietly away when I have my head turned.  Only rarely does it bow out with a crescendo and a sense of completion.  But the fact remains that what I see today is not what I saw last week or last month.

Inexplicably, trudging turns into skipping and twirling, and back again to a zombie like pace.  The finish line keeps morphing into something else, because when are we ever finished?

I don't know why we do it, but my guess is that the moments of pure delight provide the motivation to seek out more of them.  Pavlov's dogs had something after all.