Here's a story from my working life. The other day I had to help a very lovely lady take her lifelong friend to live in a care home. Her dementia was of a rare and aggressive type. Quite quickly she went from being able to live independently to someone for whom home had been a very frightening place where imagined intruders stalked her when she was alone.
'She's not the same woman' said her friend as I was driving her in the car to collect her friend. It's a cry that I've heard many times before. Some choose to walk away at that stage. It is too painful for them to continue the relationship. I feel no sense of blame when this happens. But not this lady. 'Well I'm just going to have to get to know the new person, aren't I?'