The one from Míšov, Czech Republic is tribute to the running joke of nonexistent genius Jara Cimmrman

https://en.wikipedia.org/wiki/J%C3%A1ra_Cimrman

The plaque is identical in two of the photos (one from Ireland, one from Luxembourg), and the wording is identical in those two plus a third (from Western Australia). That makes me curious.

You don't think this is just a joke that multiple people thought of independently?

Some of them might be in reaction to a local event, or even a worldwide event that had no local impact. But I think they're mostly just jokes.

Was it in a Monty python sketch or something?