Old age is a sad, sad thing. I'm not even talking about decrepit old age when the body gives way and the mind wanders. That would be understandable. Sad, but understandable.
But when you know you have it in you to do a Never Ending Tour of the world, and in between all the continent jumping you take the time off to visit your grandson's kindergarten class, and you imagine that singing a few songs for the kids is a Good Thing, but the kids call you 'the weird guitar guy', and you weren't even trying to scare them, really, by singing gruesome songs with great relish...then it's tragic.