Man is a pleasure-seeking animal. He has an abundance of desires and thus seeks to create a world where he may fulfill all of them. Yet there is no one who can achieve that goal; everyone is destined to die with desires unfulfilled.
This destiny, however, is special to man — no other creature shares this fate. As is known, the physical world, the mountains, the rivers, the stars, etc. have no desires at all, saving them from the problem of unfulfilled wants.