Dementia is a terrible disease. My mother had it, and we watched her slowly die over a four year period. It’s like living through your own funeral. She could not speak, drink liquids or communicate in any way. Her body was strong, but her mind was gone. She lived to be 95, but you could hardly call that living. Living a long time is good only if you have some quality of life.
My wife’s grandmother lived 10 YEARS unable to recognize anyone, unable to see anything but shapes and colors, confined to her bed. She died the day before she would have been 103! I’ve told my family to leave one of my pistols at hand and if I ever get that bad, I’LL solve the problem myself.