Why in the world were my super and meta keys suddenly swapped?

I finished a game and found that suddenly my alt/meta key and my super/windows key had swapped positions. I tried changing from Dvorak to Qwerty and back again, and tried restarting my keyboard and then restarting my whole computer, and found no explanation for the problem. Finally I found the answer¹, which was that somewhere in my baby-in-arms, trying-to-keyboard-with-one-hand, I had switched my keyboard into mac mode, which inverts the super and meta keys and destroys my carefully crafted muscle memory. Looking up the specifics for the Planck I found² the key that does mac mods vs win mods. One keystroke and the hardware settings for swapping the keys were resolved; meta is back in range for my thumb and the more rarely used super key is over from there.

Footnotes

¹ Stack Exchange and someone described my situation perfectly. https://elementaryos.stackexchange.com/questions/24873/super-key-swapped-with-alt-key#

² There are several keymaps here but note the “Win Mods” and “Mac Mods” descriptors. https://qmk.fm/keyboards/planck/ On the Planck it’s the raise+lower+f6 keys that need to make the change; I must have accidentally done a raise+lower+f5 during the frantics and didn’t realize the change until I was back to using my keyboard with two hands later.