The first mailman on the island had used a cart that was pulled by his dog. The special current had yet to be discovered -he picked up the post every morning at the harbor.
From the beginning there was a salesman with a little market on wheels living and working on the island. Apparently these two men had hated each other, and they adapted their routes so that they would meet as little as possible.
When the market man had saved up enough money he built a store -the supermarket that still exists today- and put up signs all over the island directing everybody there. He lived in the hotel and was popular amongst the staff and guests. In the evenings he would be at the bar telling stories about all the eccentric islanders and the grumpy mailman who just seemed to make his own life much more difficult than was necessary.
It was said that the mailman resented the supermarket owner, and messed with the signs. The islanders would be wandering around, confused. They dreaded going out of their houses, but they had to, because the mailman refused to deliver their groceries.
They started to hate the other side of the island, associating it with the stress of getting lost.