Here in a different setting, where we come once a year, I can better evaluate how John's illness has progressed. The most noticeable difference is that he is even slower. It really is beginning to take him until noon most days to get dressed and be ready to do anything. That is in part because he spends time reading his email and the New York Times on the computer, but he isn't willing to do it differently in order to participate in a family activity.
He also turned down a family activity one day because he was focused on wanting to go to a favorite food store to get the nuts he likes to snack on.
His slowness and focus on his own interests also means that he doesn't do much of the cooking and cleaning up. Our daughter complained that he wasn't doing his share. When I ask him to do something he asks one of the kids to do it, until I finally complained that I wanted to ask them to do other things. He's done a bit more since I complained (and passed on the complaint that he wasn't doing his share).
Our daughter says she definitely sees a change. She says when she starts talking fast he can't understand her at all. She isn't easy to understand when she talks fast.
I'm feeling a bit resentful because I haven't done some of the things I like to do here, such as ride my bicycle. That is in large part because my daughter's boyfriend is with her, so I'm focused more than usual on family things. But John isn't, so I have less flexibility.