Last night, I was sitting outside reading quite late - like 1AM. Just couldn't sleep. I had no music, no TV, and a bottle of water. Just nice quiet time with the sounds of late-night nature. The...
Since I was a child I have not slept more than 5 hours a night, so I am often up, moving around at 3 - 4 am, much to the consternation of authorities; my parents, hotel staff, security officers, neighbors, even police, all thinking no one has a innocent reason to be awake. So I am accustomed to being approached and just act nice.
As suggested, in this case I agree with Alzheimer's as the cause of his unreasonableness.