Every day over the first half year of this year, I visited a lockdown ward of "residents," as they are called. You're right, there's nothing fun or funny about Alzheimers or dementia.
I'm not usually such a 'wet blanket' (I even have a bit of 'gallows humor'). Maybe it is because I experienced this up close and personal but this is not funny. I watched a warm, bright intelligent, woman go through paranoia and delusions to slip very quickly into a basically vegetative state where she stayed for about 14 months (whole process about 18 to 24 months).
I also watched my father take care of her, cry over her, and rage at the world because of it.
One thing I will say is that Hospice is one of the best things I have ever run across. They were absolutely wonderful people. I urge everyone to give to them.