Good advice, thanks.
Serious photography, with serious, personally-owned equipment, is one of the skills I use at work. I can now "be" a photographer, which does not necessarily mean making a dime. I may decide to attend the Photo Plus Expo in NYC, in late October. In 2018, I may attend a week-long flash photograhy workshop, in the Rockies, taught by Syl Arena. I have attended two of his one-day "Intensive" classes, which merely scratches the surface, compared to a full-immersion workshop. Then, there is outdoor photography. Even without traveling, I have opportunities, living along a major migration route, which attracts bird photographers from all over the world.
My wife volunteers with CERT, and the county OEM, especially doing moulage work for disaster drills. (Make-up and small-scale prosthetics to simulate injuries.) Her health makes it difficult to lug the equipment, so I can help her more with that. I might be able to network while doing this, perhaps leading to a post-retirement career, should I decide to go that route.
Travel is another big one, too. Retracing the routes (and roots) on my mother's side (Scots-Irish) is one project. My father's side is not so easy to trace, here in the USA, but it is a very unusual surname, concentrated in Nancy, in Lorraine, France, so I want to connect with the area. My wife's family is Polish, and she speaks fluent Polish, and has a working knowledge of Russian, useful in Eastern Europe and Israel. (She has friends in Israel.)
Yes, if/when the grandchildren do not keep me too busy, I have plenty to do.
Of course, I can try to be a firearms/defensive tactics training hobbyist/junkie.
It would be interesting to see if I can survive another ECQC, after being away from that level of training since 2006.