Part of the art of choosing difficulties is to select those that are indeed just manageable. If the difficulties chosen are too easy, life is boring; if they are too hard, life is defeating. The trick is to choose trouble for oneself in the direction of what one would like to become at a level of difficulty close to the edge of one's competence. When one achieves this fine tuning of his life, he will know zest and joy and deep fulfillment.