Aging.

Being a seventy-year- old man is like having a twenty-five -year-old television. There's a good chance it will work perfectly for another ten years, but it's not likely. At the very least a few parts will need to replaced, if one wants to bother and if they still exist. It will be obvious to everyone that it is not a recent model.  And, of course, you always wish you had a more up-to-date features and that it was clearer, easier to hear, and more portable. Then one day when the picture starts to go everyone, except a few diehards, will agree it's not worth saving. That's when you have to remind yourself of all the years of pleasure it brought you and appreciate that nothing lasts forever.