The more we get what we now call ‘ourselves’ out of the way and let Him take us over, the more truly ourselves we become… It is no good trying to ‘be myself’ without Him. The more I resist Him and try to live on my own, the more I become dominated by my own heredity and upbringing and surroundings and natural desires. In fact, what I so proudly call ‘Myself’ becomes merely the meeting place for trains of events which I never started and which I cannot stop. What I call ‘My wishes’ become merely the desires thrown up by my physical organism or pumped into me by other men’s thoughts or even suggested to me by devils… I am not, in my natural state, nearly so much of a person as I like to believe: most of what I call ‘me’ can be very easily explained. It is when I turn to Christ, when I give myself up to His Personality, that I first begin to have a real personality of my own.

— C.S. Lewis, Mere Christianity

Creatures are not born with desires unless satisfaction for desires exists. A baby feels hunger: well, there is such a thing as food . A duckling wants to swim: well, there is such a thing as water. Men feel sexual desire: well, there is such a thing as sex. If I find in myself a desire which no experience in this world can satisfy, the most probable explanation is that I was made for another world. If none of my earthly pleasures satisfy it, that does not prove that the universe is a fraud. Probably earthly pleasures were never meant to satisfy it, but only to arouse it, to suggest the real thing.

—

- C.S. Lewis, Mere Christianity

This quotation of Lewis’ came to mind when reading this article on CNN about people becoming depressed because they cannot retreat to the fictional world of Pandora from the film Avatar.  Personally, I think this longing represents what Lewis is talking about above.