I don't believe that heredity is destiny. There are too many variables involved in the mix.
That is so true. Even those who have already been diagnosed with an hereditary condition may find that its rate of progression is not necessarily the same.
And many of us(myself included) most likely won't have a lot(or any) family help as we age. I guess my son could manage my bill paying online for me if needed. And if I stay in this area, hopefully one or two of my friends could possibly be in better shape than I if I needed some help occasionally(like a lift to the doctors). Otherwise, I would hire someone for some help in the home. There are many agencies springing up with licensed and bonded workers. I might also consider a move to an apartment or an assisted living if needed.
With bill paying via automatic bank deductions being so easy these days, I don't really pay my bills even now. I just check online to make sure that no unauthorized deductions were made, but this has not been a big problem. If/when I become extremely old, I will probably need to give someone power of attorney but that person doesn't need to be a relative.
I will probably hire a housekeeper and a gardener eventually; I already have someone to mow my lawn. I plan to gradually stop driving over the next 10-15 years. I am sure that Frank would take me anywhere I need to go, as long as he is alive and driving, but I will be able to manage without that if/when that becomes necessary. If I need a ride to the doctor's, I can call a cab. I hope/plan to live within walking distance of the grocery store, but could call a cab for that too if necessary. With cell phones, it would be easy to get around by cab and the cost is not so much when you consider the cost of car insurance and car payments.
Eventually I will probably sell my home and move into a continual care facility, so that I don't forget to take my medications and to have someone check on me now and then, so that I am not found wandering and lost, or hurt and unable to call for help, as old people sometimes are. No big deal. These facilities are not like the old time nursing homes any more, and can be an enjoyable place for the elderly to live. Besides, if you pick your facility well, you will have great meals available with lots of healthy fresh foods, and when a person is old that sure beats lugging them home from the grocery store and cooking. In my mother's facility she had a stove and refrigerator in her apartment, but after a few weeks she decided she liked the meals in the common dining hall better. Her facility had a beautiful lush garden, with paths and benches along the paths, shallow ponds, and bird feeders, so although this area was not huge she wasn't isolated from the beauty and tranquility of nature.
Adjusting to life as a very elderly person will not be easy or simple, and as we age some of us become more rigid about what we want and prefer things the way they are. But that adjustment can be accomplished and life as a very elderly person can be a joy. The sooner we start thinking about the changes we may have to make, the longer we have to adjust.