My experience with Jan has been that, once the dementia started to kick in, things did go downhill fast.
But that is in terms of comprehension, or our ability to communicate through speech. Now she is a challenge to 'talk' to - most of the time I use physical means to comunicate - touch, cuddles, squeezes. Because she is losing even the ability to crawl now, we often spend my visit on our backs on the floor mattress, with occasional leaps by me as she tries to lever herself up by putting her bony elbow in some rather painful places.
Jan is still strong as an ox, and she still eats more than me each day.
My point is that there is a difference between comprehension and the physical.
For Jan, already 15 years into this, she - and I - could be facing 2, 5, 10, 15 more years of physical decline before a virus hits her. Or it could hit her tomorrow.
She has declined physically, but that is in terms of her ability to stand, walk, look after herself in any way, to see, to speak, and slowly, her ability even to crawl on the floor.
That is the challenge. Nobody knows how long we have. There can be no planning. There can be no future that is comfortable for either of us. I'm on edge all the time and I dread phone calls that come in the evenings, unexpectedly.
Other people with dementia, about the same age as Jan, have moved into her home, and had become rapidly worse within the space of 6 months, and died.
Jan is strong, and in a bizarre way, I'm very proud of her for fighting so hard; I tell her so.
But I wish she would stop doing so, and be at rest.
I have no idea how I will handle that, whenever it happens.