"Why do you guys drive on the wrong side of the road when the rest of Europe does it the other way? "
Actually, the left side is the correct side. The reason appearantly comes from the knights, as their right side was the weapon side and striking things to the left of you was more difficult than to the right.
I've seen the same references in Japanese samurai customs. To walk along a samurai on his left side, uninvited was considered a potential threat.
Daff