Everyone knows which side to drive on.
(If you don't, ask someone what country you're in, and check the list on the link below.)
But, why? Well, there are many different and interesting reasons for choosing one side or the other, listed on the WHICH SIDE? site.
Right-siders are in the majority, 66% by population, 72% by road length, but that still leaves lots of left-siders. To drivers, the correct side seems basic and almost instinctive, whichever the local custom may be. Considering this, we might well examine other basic assumptions, having to do with our acceptance of other people and the ways they choose to do things. Too often we decide our own custom, belief, lifestyle, sexuality, etc., is right, and the others are wrong.
The more we get to know about our neighbors in the world, the more we need to learn tolerance. And when we finally meet an extraterrestial, we'd definitely better be able to accept some differences.
Check out the road-side siteWHICH SIDE?