I tried an experiment on my walk to work today. I walked on the left side of the sidewalk. Then I looked off to into the distance, pretending to be fully engrossed in whatever was happening over there.

People who were walking the other way, coming towards me, refused to change to the other side of the sidewalk. They saw that they were going to bump into me, that I was not paying attention, and they still would not move to the other side of sidewalk.

Isn't that strange?
There's no LAW that you walk on the same side that you drive on. And yet, it seems that there is. In fact, people are quite adamant about it.