I’ve been hanging around a lot of elderly folks recently, very elderly, and I don’t know what to say to them. I am so much younger. The techs put me on a completely different treadmill way off in the corner (at one point I am actually running), and on totally different resistance settings on the cardio-bike. “I don’t feel like I belong here,” I told my wife after the first day, as she picked me up outside the medical center. (I am not allowed to drive for a month.) I sat in the pass...