dementia. In her case, yes, she became aware in her mid-70s (around 2012) that something was wrong. Those of us around her frequently did as well. Her most apparent sympton to us was she would frequently have trouble finding a word she needed to use. Then, she would have brief lapses in her recent memory. She was very aware she ws having issues.
She ended up under the care of a neurologist. An MRI found quite a bit of plaque in her brain.
In 2018, she fell down their front porch stairs and broke her clavicle and wrist. She required surgery, and over the course of about a week after, we lost her mentally. I dont know if the trauma of the fall triggered something, but she went downhill very quickly over a matter of just a few days. She went from the hospital to a nursing home and lasted about eight months.
The last months were awful. She would have ocassional bouts of lucidity and talk some. Eventually, they had to put in a feeding tube and in the last couple of months she just laid there in a fetal position. She might open her eyes and follow you around the room, but never spoke. Then, she would just stare if she opened her eyes.
My hope has always been that well before she passed that she became totally unaware she even existed.