We are born into a realm of constant change. Everything is decaying. We are continually losing all that we come in contact with. Our tendency to get attached to impermanent experiences causes sorrow, lamentation and grief, because eventually we are separated from everything and everyone we love. Our lack of acceptance and understanding of this fact makes life unsatisfactory.
Nature is comforting. If you are close enough you can feel the negativity you carry being drawn out from within your core, seeping peacefully away into the scenery. Nature is forgiving.