My ears are attuned to every little sound: the clicks of the break release handles on Dad’s downstairs walker; Mom’s syncopated shuffle; the single beep as the stair lift arrives at the end of the track, upstairs or down; cursing from the bathroom. This morning I awoke to the muscular sound of an industrial-strength vacuum in the master bedroom.  Through the doorway I saw Dad sitting on the walker seat and pushing the carpet cleaner forward and back next to the bed.  I did not ask, but I knew without asking.  His weekday CNA Cecilia—faithful, pleasant, and kind—came shortly after and helped him shower.  From my home office I could hear their one-way conversation: she said very little.  “Do you know how old the earth is?” he asked her.  “Four and a half billion years old!”  He knows and loves the Bible and its God, but informed Cecilia that “God did not make the earth in six days.”  Rather, He probably took billions of years to make our globe.  Dad explained to her about the sun burning hydrogen in nuclear fusion, with enough hydrogen still to burn brightly for billions of years more.  He told her that the only way we know how to use nuclear fusion reactions is with a hydrogen bomb, and referenced the atom bombs dropped on Japan.  He expounded about ocean currents, and about the hydrologic cycle of evaporation and precipitation and the rivers of water vapor coursing through the skies, and about Argentina’s defiant propensity to default on its international debts, and about the formation of galaxies and stars.  “I like to know things,” he summed up.  Cecilia, an excellent listener, interposed an occasional affirming “really?” and “oh.”  He told her about our family visiting an Indian tribe in Brazil in 1974, and how the tribal elders would not let us into their compound without being members of their tribe, and about how the tribal elders allowed us to become members of their tribe by following them on a course through the grounds and buildings, ending at a ceremonial tree, and about how we bought blow guns and bows and arrows from the indigenous women of the tribe.  This is a true story.  I know because I was ten and I was there.  Dad’s stories sometimes jump from one unconnected subject to another, shifting like an old car with a worn out clutch.  Dad lamented to Cecilia, “A few months ago I was a normal person.  I could walk.  I could do things.”  That is not true.  I know because I am 58 and I have been there with him, watching the insidiously steady downward degeneration culminating in painful undignified immobility and having to use the carpet cleaner in the mornings.  He is not untruthful—he just forgets.  And he cannot retrieve his books from his bookshelves or his checkbook from his desk or a glass of ice water, and has to ask Mom and me to fetch these and other things for him.  He asked me to bring him Mom’s youthful portrait from his desk, placing it on the end table by his recliner, where he can see it all day as he reads.  I remember seeing that portrait of Mom on his desk thirty years ago when I visited his New Brunswick office in the Johnson & Johnson tower.  He has gazed at Mom’s youthful portrait for more than six decades, and he tells Mom everyday what a wonderful person she is, and that he loves her.  And he steals hugs when she walks by, and she returns the hug and runs her fingers through his sparse wispy hair.