LAST YEAR, THREE DAYS BEFORE MY BIRTHDAY, I had not yet relinquished my hold on the younger of the two ages, the one I could still claim for the next 72 hours. Although being a senior citizen was no longer a shock, that didn’t mean I had accepted the label “old.” Because of my impending birthday, however, I was more focused on my age than usual, wondering how many more years I would be allotted.

In this state of mind, I exited my car for my weekly half-mile lap swim. An old man was just entering the pool building; I followed a minute later. When I opened the second door, which leads to the pool area, I reared back in surprise, nearly stepping on the selfsame man. He was wedged into the corner on the wet cement floor, his legs tangled beneath him.