...that my computer was not broken.
I had trouble getting it to turn back on from sleep mode after lunch, and re-starting didn't help either, so I ended up calling one of the computer shops in town - actually I called two. The first one told me "you'll have to come in and bring it so we can have a look" and then the second one called back (he didn't answer on my first attempt) and told me that in 50% of such cases, it's a hang-up in the BIOS and I could try to fix it myself by taking out the battery, doing a few longer power button presses, and then powering it back up.
To my very, very great relief, it did work! Because buying a new computer and getting everything settled with the new machine was really quite low on my list of things I'd currently love to do. It did bring the bonus insight that the battery is old and starting to turn into a more rounded shape, so a new battery is now on its way. (Via said computer guy - so he's at least getting a little bit of profit from helping out.)
So now I can do the printing that was not possible after lunch, and get stuff ready to go into the post tomorrow (instead of today). Whew.