It feels like in almost every office kitchen I've been in in Norway there is some sort of label that say something that is supposed to be witty like: your mother does not work here, tidy up after yourself.

It mostly doesn't work.

Three places I worked had tidy kitchens. None of them had these labels, but more importantly: in all three of them management would fix it if others didn't. I guess most people only see their bosses boss tidy up a couple of times before they realize everyone is supposed to do that.