I had trouble sleeping throughout my late adolescence and for the first, I don't know, thirty years of my adult life.

It wasn't until a couple of years ago when I began working from home that I accidentally standardized on the hours which seem to have suited my body all along. I go to bed between one and one-thirty in the morning, and I wake up -- without needing an alarm clock -- between nine and nine-thirty. And most nights I sleep soundly enough that I haven't renewed my Ambien prescription (which, honestly, only ever helped a bit more than any of the many other sleep aids I've tried) in years.

But I'm not always sleeping soundly these days. There has been a trend of recent deterioration.

Some of it is just the climate. No, not the weather; the political climate. It's hard to have a diet of the fifty thousand ways the world is completely falling to pieces all day long and then go to bed without mental indigestion.

Some of it is that I have developed an arthritic knee (which I'm going to talk to my doctor about any minute now, honest) which, on its bad nights, makes it very difficult to find a position to sleep comfortably in -- which is something I already had problems with even before this.

Some of it is the bedroom in which I sleep (we sleep separately because we keep such very different hours, and also I fidget and snore) is the hottest room in the house, at least on the nights when our whimsical radiators decide they want to earn an honest living.

I also have come to believe the nonexistent ventilation in there (I sleep with the door closed because I don't want the cat coming in -- I'm scared I'll roll onto her and not realize it) isn't doing me any favors.

I'm considering buying a small carbon dioxide monitor, just to see exactly how many ppm are kicking around in there every night.