This is so frustrating. And, I mean, intelligence isn't the only thing in the world, but he used to be so smart and able to spot health disinformation in particular.
I keep thinking of a memory from when I was 12 or maybe as old as 14 and I was sat behind him in an auditorium. I saw he had grey hairs - it was the first time i noticed them. And I had the knowledge for the first time that he was aging and wasn't immortal.