Okay, my plan obviously is to try my best to avoid getting dementia in the first place. And I have learned plenty about diet and exercise and lots of other factors that may reduce my chances.
But you spend this much time with someone struggling with it, and you cannot help but consider. What would I do?
I notice that Mom does best with habit, so I would be focused on setting up a life that could become as habitual as possible to have some life quality for as long as possible. It seems that people become increasingly complicated, so anything too social is likely more stressful. But, getting out and interacting or having some significant stimulation on a regular basis is a good thing.
After some consideration, I decided on my plan. At the first signs of serious memory loss, I would move across the street from a really good zoo and make a daily habit to walk there. Every day I could see elephants and frogs and tigers. I have always loved animals so this I think would keep me well entertained for a long time into dementia. My dad always said that he thought I would grow up to do something with animals from how much I loved them as a kid, so the childhood regression that seems to happen would fit nicely.
So that is the plan. Obviously there will be steps after that but from what I have seen of these years with Mom, there is some living to fit in.