Today was a difficult day; I basically couldn't sleep last night and so it was no surprise to find that today my brain was on some other planet.  Not helping was the possibility that contractors would be coming to finish some repair work on the roof of my home (basically it's a chimney repair and recap, which is relatively minor as roof work goes), and the uncertainty about whether and when (it turns out to be tomorrow) screwed up the timing of stuff a bit.
I had extensive notes for the midterm paper I'm working on for my summer course, so I was able to somehow finish putting a rough draft together, which I subsequently sent off to the professor for feedback.  The final draft is due Thursday so there is some wiggle room left.  The extent of my notes definitely saved my rear because without them today would have been a total loss, my brain was that fried.  I honestly wished I could have spent the day in bed.
One odd thing that did come out of it, though: When I went to my training session late this afternoon, the trainer was in no better shape than I was.  He, too, was half asleep, in part because he just moved to the area and has had to deal with a couple of very long nights this week.  Between the two of us, it was definitely not out best session.  But we were both my equivalent of mentally baked, so this will probably be easier to let go than most.