Grr. My brain cannot bend like that.

I have no idea how my cat did it, but he managed to change the settings in Windows 10 on the computer at home so that one monitor's video was oriented 90 degrees CCW and the other monitor was a full 180 degrees out.  On top of that, I think he managed to get the CTRL keys stuck "on" in some exceedingly sticky and silent way.

I'm assuming it was the cat, anyway.  I do have two toddlers.