Am I just getting old?

Today I visited with my friends and reconnected after the trip, watched UK beat Auburn in the SEC men's basketball semi-finals  with one of them, and then took him to the grocery, and now, less than 24 hours after getting home from Chicago, I am already ready for a nap, even though I've done nothing strenuous and I've walked about a fifth of what I did Thursday. Now granted, on the first week of Daylight Savings Time, I've bounced back and forth between two time zones, really exerted myself over the course of three days, flown twice, etc., but still, I thought one good night's sleep would get me back to normal.  Of course, come to think of it, I was up for an hour in the middle of the night because, well, that's what I tend to do--I wake up and it takes awhile to go back to sleep.  So maybe I didn't sleep quite so well.  But I did dream vividly, something I don't remember doing at all during my trip.