"It all began one morning last July when we noticed a young man of twenty-six crying in his bed in Dr. Pitre's ward. He had just come from a long journey on foot and was exhausted, but that was not the cause of his tears. He wept because he could not prevent himself from departing on a trip when the need took him; he deserted family, work, and daily life to walk as fast as he could, straight ahead, sometimes doing 70 kilometers a day on foot, until...