There have been many articles written and survival experts claim that you can tell cardinal direction by the side of a tree that moss grows on. The premise is that moss only grows on the North side of trees to shun sunlight. This is simply not true.
Moss will grow wherever it can find moisture. If the south side of a tree you are looking at is partly shaded by another tree, then moss will colonize it. It may be that in certain places and under certain conditions that moss grows predominantly on the north side of trees, but not enough to recommend relying on the moss to find your way.