While in Napa, playing with my grandchildren, I got addicted to the puzzle game Sudoku, downloaded it to my computer and have playing it on the train-ride home

Without going into the intricacies of Sudoku, I need to copy an 81-cell grid that's on my computer screen right in front of me onto a piece of paper also in front of me. The grid is divided up into nine squares of nine cells each, and I need to mark with an X the cells I've completed and leave the others blank.

It's a simple task: copy a design that is right in front of me.

I just can't do it; not even close; I become repeatedly confused. I've posted about other experiences of getting confused; although in those situations I was confused about much more complicated matters. But this is straightforward copying, and I can't do it.

Immediately afterwards, I was editing an essay I'm writing and I got confused again, too confused to continue. Then I tried reading a simple novel and got mixed up there, too.

Have I suddenly gotten worse? What can have caused it? If the cause of my cognitive decline is vascular (little strokes), have I just had another shower of the tiny clots?

It seems that my life has turned again.

## A passing moment

Several hours after the episode above, I came back to my reading and then to editing, and I was able to do both without difficulty. Just yesterday, a week after the events above, I had no difficulty in copying a similar pattern from a Sudoku game.

So it was a temporary event.

It could have been something akin to a transient ischemic attack (TIA), but I doubt it. I suspect it was something much simpler. I don't sleep well on the train (to say the least) and was extremely tired. I was also wired on caffeine, which I ordinarily don't drink much. I'm beginning to think that the physical stress I was under from the tiredness and from the caffeine significantly exacerbated my cognitive decline.

Come to think of it, my trouble calculating the speed of the tips of the wind generators we passed occurred on the train out West, when I'd also been short of sleep (and probably wired on caffeine, too).

Hard as it may be to believe, I've never thought of this possibility. Could other exacerbations of my underlying cognitive decline have been similarly affected by physical distress?

If physical stress is a major contributor to my episodes of worsening confusion, then I need to think seriously about decreasing that stress.

It's the lack of sleep that is the most likely culprit. I've never slept well and can say that I've been chronically tired a great deal of my life (except during certain vacations). Part of it is anxiety, part of it is my history of depression, but much of it, I suspect, is that I just enjoy the late night so much and can't discipline myself to go to bed. This kind of change could be very problematic.

In certain ways I've taken good care of my body throughout my life: lots of exercise, reasonably good diet, normal weight, and so on. I have not, however, ever given much thought to my chronic tiredness. It's time to re-examine things.