by the time you are showing classic symptoms, it may be too late, dementia gradually develops over the decades but people usually attribute the classic symptoms to usual aging, shit memory, 'senior moments'

so the ability to actually progress the facts may be diminished.

i think i would focus on making a good will, and living as much as i could before i was totally fucked.

Peter attia had a very interesting pod on dementia a while back with Lauren Miller Rogen https://peterattiamd.com/laurenmillerrogen-richardisaacson/

her whole family basically gets dementia but she was early to spot the symptoms and was able to do a lot to halt the progress. worth a listen