Prince Harry is a man in search of a purpose. That much alone is clear from the title of his book, Spare. At one point, as the third in line to the throne, Harry lived his life as the “spare”, only “necessary” should his brother William meet an untimely end. He is now seventh in line, not exactly a “spare” so what to do now? The search for meaning dominates. Harry is rarely happier than when at the controls of a £42 million Apache helicopter, gunning down Taliban on motorbikes. “I can tell from the way you fly,” an instructor...