I think everyone here will know who this is about. At this point in his reigns of error, either one works for me.

[ms liberty]

12. But thats not really how it works. Dementia robs a person of their ability to understand they are ill

There is a period where they realize there's something wrong. The know that they're hearing/seeing things that aren't there or true, and during that period it is living hell for them. But that's just a brief stage in the journey. Once that period is over, they do not realize that they're the one who is cuckoo for cocopuffs - they live in and believe the delusions and hallucinations they are experiencing are real, as real as anything can possibly be.
My MiL was diagnosed with dementia; I had retired early to take care of her after a bad fall, then her diagnosis came soon after that. I looked after her until we had to put her in a facility; she passed April 27th. It was hell at first; one day she would think we were trying to kill her and take all her stuff and the next she would be mortified, crying and heartbroken that she had been so cruel to us.