[zfxfr]

This is weird because this is the kind of game you know you have played at least a couple of times a long time ago before, you instantly know how to play it but I personally cannot remember where nor when.

[kxrm]

Not sure where you are from but if you go to any Cracker Barrel in the US one of these puzzles can be found on your table.

[dvh]

Another evidence for Last Thursdayism.

[ljf]

Never heard of this - https://en.m.wikipedia.org/wiki/Omphalos_hypothesis#:~:text=... for those interested