I had a similar debacle, when I managed to corrupt a btrfs file system to point it wouldn’t mount again…

I was preparing it to have as my main system on bare hardware. I had accidentally mounted the same block device simultaneously in the host and guest: kablamo silent corruption and all 5 hours of progress lost.^* :(

*shred the guest VM, host was ok.

On arch, UEFI boot vars are mounted at /sys/firmware/efi/efivars. It’s unwise to rm -rf them…

GameBoy Color with a single game: Pokémon Red.

Next time I was able go to the shop they had upgraded to GameBoy Advance and no GB/GBC games were to be never found again. It was the best/worst thing I ever got. :'(