Remorse
Many forms of life feel sadness. But, remorse is reserved for humans, and unknown to all other creatures. A thousand year old redwood giant by fate and destiny must topple over, and with no regret, none whatsoever. A tiny spider completes a final web, then casually dies in its corner, no prey of remorse entwined. One day, long from now, a very senior owl in its last frozen moment will bow down in deep silence, into the snow, as if the normal course all along, another departing winter, no remorse.