I somehow managed to factory reset my Kobo that way a few days ago. It had frozen, so I held the power button for a few seconds as I usually do when it freezes. Didn’t work, so I held it a little longer.

And suddenly, BOOM, it comes back to life, shuts down, and heads into factory reset town.

I did a few swears, then set it back up, reset the sync to Grimmory, and got all my books back.

Stoopid shit.