It's the empty feeling that keeps driving us onward. Life's a journey, not a destination. Except for brief periods in their lives, I don't really know anyone that does not feel empty. People in big close families and married people feel lonely a lot. You can feel lonely in a huge crowd. You can feel nostalgic for some past Golden Age that all the present day material comforts can't hold a candle to. Maybe emptiness and loneliness is just the human condition. Maybe we were designed that way so that we, as a social species, would continuously seek connection.