Exactly - there are things that I would change now to make sure I make thing easier for myself and - more importantly - easier for the people around me.
I think there are many people (myself included) whose plans would change dramatically upon discovery of Alzheimer's, dementia, or some other degenerative disease. I might consider moving to somewhere with more liberal assisted suicide laws for example.
Notarizing any wishes against some medical procedures in case a sudden accident ruins your ability to dissent prevents doctors from being forced to keep your body alive as long as possible.
That doesn't apply to Alzheimer's disease directly though. If you don't want to live when your conscious life is limited to short flashes of awareness among a deeply terrifying melange of visions of the past and hallucinations, DNR laws don't in any way force or even allow doctors to euthanize you. You can persist in this state for many years without ever triggering a DNR check.
My genetics are such I'm more likely to drop dead of a heart attack too young.
If I were likely to develop alzheimer's, I'd make more and more expensive accommodation for power of attorney and trusts to shield assets while I was competent to do so.
Like what? You should already have a will, life insurance, etc. even without the disease. All you're doing by knowing earlier is causing psychological harms to yourself and the people you tell, adding more years of anxiety, grief, and sadness for no gain. Think about the bigger picture.
