I'm not so sure his family takes care of him in a good way, they are really old and what happens when they die?

I really can't know what is wrong with him and I hate that. I mean I can't just be sure this is dementia. I'm basically sure he has not been told it is. If the family has been told, IDK it just seems so weird not telling the patient.

I also have a pretty bad experience with family and brain disease. I used to have a friend with a type of brain disease and I could see something was wrong, she couldn't type right and she told me her eyes were jumping all over the place and she didn't have much balance at all. She was basically clinging to walls while walking. I knew all that over the Internet. When she finally got diagnosed much later the family said they hadn't seen anything unusual with her despite that she could barely walk anymore. Sometimes it's the families that are in denial.