Years are curious units of measure. In some ways they seem to tick by quickly and blur together. Yet in recollection they stand as distinct layers, around which our character, worldview and sense of purpose are built.
On trees, growth rings visibly tell the story of a series of annual atmospheric events. As humans our layers are not so easily visible, but for us too each year adds additional colour and depth.
In some ways the trees live as we do. Some years we face fires, some we suffer drought, and some we just pass. While Nietzsche probably oversimplified in suggesting that the path to growth is through trauma, I do agree that when the going gets hard, those still standing get good. Maybe I am an optimist. Either way, the good news is that we get to give it all another go in 2018.