Just writing that makes my mind start to churn with other possibilities for "down time". Could I have done something refreshing and relaxing and restorative that ALSO edified? In other words, something that wasn't a total time-waster? Undoubtedly. But I didn't think of that question then. I thought of it now. And so it goes.
Back to my point, such as it is - Sudoku. I had a book of these puzzles a few years ago and worked through it and discovered something. They are not hard. Nor are they especially mysterious. They are simply fill-in-the-blank tests with clues. The only thing we don't know is how long it will take to solve it.
And it will get solved. This is why they are less than puzzles; less than mysteries. We know the answers, it's just a matter of time. And I finally decided I don't want to spend a half an hour finding 9 sets of numbers that run 1 through 9.
So, how do you spend "down time"?