There is more than one aspect to memory. Of course there is the physical, where there is damage, through injury or disease,and of course the increase in memory with the continued establishment of both knowledge and associations, where memory can be improved by creating links between existing memories, and new experiences.
There also seems to be shedding of recent memories, when what has been remembered most fondly has disappeared. Forgetting because there seems to be no motivation to remember. There is also the case of trauma that has not been resolved, and what should have been a memory in a time line, can overwhelm others - leading to flashbacks phobias, and obsesions.
I have seen two sist...

There is more than one aspect to memory. Of course there is the physical, where there is damage, through injury or disease,and of course the increase in memory with the continued establishment of both knowledge and associations, where memory can be improved by creating links between existing memories, and new experiences.
There also seems to be shedding of recent memories, when what has been remembered most fondly has disappeared. Forgetting because there seems to be no motivation to remember. There is also the case of trauma that has not been resolved, and what should have been a memory in a time line, can overwhelm others - leading to flashbacks phobias, and obsesions.
I have seen two sisters, my Nan, and my Great Aunt, who had completely different ends. When my Great Aunt's husband died her memory seemed to die with her. this was no doubt compounded by the fact that many years ago her son had also died. Before she died she seemed little more than a shell. There seemed to be a history of memory loss, perhaps Alzheimers disease in the family.
My Nan was proud of the fact that she had lived longer than any of her relatives, and she was also terrified that her memory would also go, but she was involved in most of the family events, and quite often said her grandchildren gave her "Plenty to worry about" While the 'worry' may have kept her mind busy, it was usually relieved when things turned out ok. She also hated the 'Memory Doctor' my aunt arranged for her to see - she said she was on enough pills already.
She was sharp until the day she died.