Life is a process of becoming, a combination of states we have to go through. Where people fail is that they wish to elect a state and remain in it. This is a kind of death.
Love never dies a natural death. It dies because we don't know how to replenish it's source. It dies of blindness and errors and betrayals. It dies of illness and wounds; it dies of weariness, of witherings, of tarnishings.