When I turned fifty I understood how cars feel when their warranties expire. If cars feel anything when their warranties expire. On December 9, 2015, two months after my fiftieth birthday, I ended up in the hospital with a kidney infarction. I felt slightly upset — and also slightly betrayed — that the odometer had barely rolled over and a major system went on the blink. But it did, and there I was, for four days, mostly reading and watching TV between nurses’ visits to draw blood, take my blood pressure, and check the heart monitor hanging around my neck.