I think I've figured out my problem.
The Alarm Clock Time here at Roseholme Cottage got bumped back to 0500 a couple months back, in the interest of getting breakfast cooked, internets read, and Roomie ready for work at a reasonable hour.
However, I have still been hitting the hay at the normal time, and sometimes later. For instance, last night I was smokin' tangos 'til 0MG30 and then woke up and tried to do the normal writing and stuff on less than five hours of sleep.
No wonder that when I stopped at a store while I was out shopping, I was so disoriented that I thought "If I go in and find the place has been replaced by a dry cleaners, and the staff has no recollection of any previous tenant, I won't even be the least bit surprised..."
From now on, 2200 hrs is a hard bedtime...