I must say a word about fear. It is life's only true opponent. Only fear can defeat life. It is a clever, treacherous adversary, how well I know. It has no decency, respects no law or convention, shows no mercy. It goes for your weakest spot, which it finds with unerring ease. It begins in your mind, always. One moment you are feeling calm, self-possessed, happy. Then fear, disguised in the garb of mild-mannered doubt, slips into your mind like a spy.
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Quickly you make rash decisions. You dismiss your last allies: hope and trust. There, you've defeated yourself. Fear, which is but an impression, has triumphed over you.
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[Fear] seeks to rot everything, even the words with which to speak of it. So you must fight hard to express it. You must fight hard to shine the light of words upon it. Because if you don't, if your fear becomes a worldess darkness that you avoid, perhaps even manage to forget, you open yourself to further attacks of fear because you never truly fought the opponent who defeated you.

-from Martel's Life of Pi