I know what you mean, Baseball. When dealing with my late mother's Alzheimer's more than a quarter of a century ago, I would say to my wife after a particular bad episode, "I hope MY body does not outlive MY mind." That was for two reasons. I don't ever want to suffer like she did, and I don't want my kids ever to see me behave like that.
Agreed, but I want to mention that there is available a healthcare directive that enables a person to specify the levels of medical care he or she desires through the three stages (mild, moderate, and severe) of Alzheimer's. The choices available at each stage are: (1) To live for as long as I can, (2) To receive treatments to prolong my life, but if my heart stops beating or I can't breath on my own, I would not want my heart shocked to restart it and I would not want to be put on a breathing machine, (3) To only receive care in the place where I am living. I do not want to go to the hospital even if I were very ill, and I would not want to be resuscitated, (4) To receive comfort-oriented care only, focused on relieving my suffering such as pain, anxiety, or breathlessness; I would not want any care that would keep me alive longer. Here is the link to the form:
https://static1.squarespace.com/sta...f87698d1/1623530793274/dementia-directive.pdf
I suppose one might rationally choose different levels of care at the different stages. Unfortunately, I don't think my wife has the cognitive wherewithal to complete such a directive even though her Alzheimer's probably is late mild stage or early moderate stage, so I suppose the lesson is not to wait too long.