A hobby that I had back in my 20s and 30s, which I have recently started up again, and which has resulted in me working on a book, is genealogy. It’s a hobby that is a lot easier now given the Internet and it’s one that has classically attracted older folks, because you can spend a lot of time going down the rabbit hole, which is easier if you’re retired or less employed.

Another old person hobby that I have had since I was young is birdwatching. It is a little dependent on mobility and vision, but not as much as you would think. I knew a very old guy once who could barely see and one of his favorite things to do was have a friend drive him near nature sites, and he would identify bird calls from the car. Birdwatching is basically slow hiking for nerds.

I build models. Granted it is much more expensive than it was when I was a kid and it’s very dependent on the status of your eyesight, but it’s still a fairly easy and homey hobby.