I think the point is that the author claims this is everything he knows, but it obviously is not. Does he know how to tell time? It’s not in the book. Maybe th

I think the point is that the author claims this is everything he knows, but it obviously is not. Does he know how to tell time? It’s not in the book. Maybe the author did not mean to be taken so literally. But, really, it’s not possible to write down everything you know—and taken literally, it would lead to an infinite regression (now I know that I’ve just made this note about what I know, so...). It’s impossible not to be selective, to choose what’s worth writing down.