The world has a lot of different standards for a lot of things, but I have never heard of a place with the default screw thread direction being opposite.
So does each language have a fun mnemonic?
Photo credit: https://3.bp.blogspot.com/-Giy8OrYJTjw/Tfm9Ne5o5hI/AAAAAAAAAB4/c7uBLwjkl9c/s1600/scan0002.jpg
If I remember correctly, old timey glass kerosene lanterns also have backwards threads for some reason
Gas threads and water threads are opposites to each other for safety reasons. Might be part of that thought.