He no longer remembers what day it is, or what was said in conversation twenty seconds ago. His early memories are still mostly intact, but he has lost significant portions of his vocabulary, and has obvious difficulties forming sentences and remembering nouns. He still recognizes us unerringly, and remembers where he lives, and functions on his own tolerably well.
But it's clearly deteriorating fast. As recently as four months ago, he never lost track of what day of the week it was, for instance.
He used to be quite obviously depressed and miserable (he was quite shattered by grandma's death), but I can no longer tell what he feels. I hope the disease has at least taken the load off his heart. I just have no idea what he feels or thinks of all day. I doubt he can enjoy himself at all. He just carries on. It's painful to see him so helpless.
I'm thinking the unutterable often.