Go learn to skateboard or snowboard? A pass--where would I go with that at my age? Learn something new related to computers? Your bar to clear to motivate me on that is huge (but it does occasionally clear). Go back and push my Quantum Mechanics or Solid State Physics to another layer? Nah, not without a good reason.
There are some evergreen computer topics, like SQL, and bash, design patterns. I focus on those rather than the latest Javascript library. But otherwise, I really want to focus on things which help me give back, communicate, or understand the world better. For example, I am studying Latin because it helps me understand the deep history of humanity, and of languages, and the evolution of thought and consciousness. I practice guitar because I realize that music is all about communication and creating special, authentic experiences. I love to get outside, and I am more interested in geology, botony, and the birds and the animals than I ever was. Because those things are deep and unchanging.
I think part of it is also about risk/reward. I can spend time learning something, but if I don't have the confidence it will pay off, I find it much harder to commit. Maybe it's about having less time ahead of you or being more cynical.
Can you ski as opposed to snowboarding? I've ridden the lifts up with many older people, 60s-70s. They are there for a range of reasons but mostly related to pastimes, escape, and enjoying it.
I don't know what older means to you, but I think you inadvertently described a self-limiting thing in your quest not to.
It's not about other older people doing it. If they enjoy doing it, great for them.
I never learned to ski or skate, so I have to ask myself why should I learn to do that instead of some other physical activity I already enjoy.
And, to be fair, as a kid I never learned to ski or skate for good reason. The kids who skied or skated always seemed to have lots and lots of broken bones. Nah, I'll pass. I've got other sports I like that don't seem to bust my bones up.
Learn another foreign langauge? Sure, why not. Learn machining? Sure, why not.
Go learn to skateboard or snowboard? A pass--where would I go with that at my age? Learn something new related to computers? Your bar to clear to motivate me on that is huge (but it does occasionally clear). Go back and push my Quantum Mechanics or Solid State Physics to another layer? Nah, not without a good reason.