Last birthday (or this one, according to Dad, whose memory ain’t what it used to be) I hit an age that was one half the age at death of my longest-lived grandparents. I had a great-grandfather who lived to be somewhere in the middle of 99 and 100, but it wasn’t insignificant to me, that halfway age. Despite that, or perhaps because of it, I joined my child in roughly 60 minutes of jumping at a trampoline center today. Dad estimated it would be Tuesday before I felt it, but I’m pretty sure I’m not going to be able to move my neck tomorrow morning and might not be able to move my back by tomorrow night. The legs still feel pretty good.