See, if you drag a bunch of files from one window to another, then realize you wanted to copy them, not move them, and hit the "undo" button, it undoes the moving of them into the new folder. But it doesn't undo the moving of them OUT of the first folder! That's right, it DELETES them. Entirely. Not moved to trash -- just deleted, wholesale. Somebody remind me why that level of UI maldesign is not grounds for criminal charges? 'Cause it oughta be.
Happily, I was able to find a fairly inexpensive data rescue program that recovered all the files with no problem. I probably could have done it much quicker, but I was feeling paranoid and let it scan the entire drive to make sure it wasn't missing anything, and it took a very long time. But I got my data back!
After an scant hour or so at work finishing off the stuff I was working on yesterday afternoon when the company's website fell over and made it impossible for me to continue, I met zalena and we went off to the tea house near Ideal Market to hang out for a bit. She handed off a couple Moomin books to me, we chatted, and I had boba tea (the kind with tapioca pearls in it). It was a pleasant antidote to computer woes.