Human stories are practically always about one thing, really, aren't they? Death. The inevitability of death. . .. . . (quoting an obituary) 'There is no such thing as a natural death. Nothing that ever happens to man is natural, since his presence calls the whole world into question. All men must die, but for every man his death is an accident, and even if he knows it he would sense to it an unjustifiable violation.' Well, you may agree with the words or not, but those are the key spring of The Lord Of The Rings

But Ilúvatar knew that Men, being set amid the turmoils of the powers of the world, would stray often, and would not use their gifts in harmony; and he said: 'These too in their time shall find that all that they do redounds at the end only to the glory of my work.