There’s a word for happy accidents, those series of unplanned events leading to good memories: Serendipity.  I am convinced the best trips are those in which we allow serendipity to go along for the ride.  On a trip to London several years ago, I did something I do with some regularity and never with regret. I had always wanted to go to Glastonbury.  It was on my “someday” list. On the spur of …