An Adage

I was pondering the adage "a rolling stone gathers no moss." If that is true would rolling moss be 'street legal?' Or possession of a controlled substance? It is just a thought! It brings to the forefront another adage. "moss always grows on the north side of the tree." I can see a couple of cronies walking in the woods. One asks the other, "what happened to the north side of the tree?" The other answers, "you know what happened to the north side of the tree as well as I do, we smoked it!" Sine Die