I just noticed this thread, and when I read the opening words I thought I must have written them myself and forgotten!!!!
Yes, I've got one too. He has lots of hobbies, including astronomy and photography, but has no motivation to do anything. Aches and pains and various health problems contribute of course, but in the end there is nothing I can do. I've tried, but I've given up.
I go to my U3A classes, walk the dog with a neighbour and her dogs, do my gardening, various sewing and craft work projects, and enjoy the internet. We have both been retired years, and are aged 70 (me) and nearly 72.
To add insult to injury, there is less and less worth watching on the telly - probably 'cos we have no interest in most sport (apart from cycling), cooking, so called reality programs, BB, and American sitcoms. So when the news is over, there is often nothing much to watch.
But luckily we both love reading, and read both real books and books online.
There IS life after DH's retirement, but not as we knew it!!