re: The age(s) between 75 and 85/90 are the worst.

Your body will break down eventually. The difference I see in quality of life of those I know 80+ is their attitude. I know so many elderly who mourn for the past: for their past bodies, their past loved ones, their past level of activity. I'm determined to not be the older person who only talks of their physical ailments or the past. I want to be the older person whose mind is still sharp and yes who suffers physically but does not dwell on it with others. Of course, my mind has to cooperate. I fear decline of mental capacity much more than physical. That's why I plan to work until about 75 then find ways to stay mentally active like volunteering and being around younger people.