“The lesson in my friend’s observation is that the line moves. What had once seemed unendurable to an aged parent, and still does to us, the adult children, changes. They come to tolerate the formerly intolerable and to surprise us with their forbearance. Diapers, it turned out, were not the end of the world. Nor was a wheelchair, despite initial resistance. Millimeter by millimeter the line was moving, as it would many times more.”