True GritThe epic true stories of heroism and survival that have shaped my life. Bear Grylls knows what it takes to survive. But he's not the first. Take the American bombardier Louis Zamperini, who survived 47 days stranded at sea by catching and killing hungry sharks and drinking the warm blood of albatrossesonly to be captured by the Japanese and horrifically tortured for years in their most brutal POW camps Or Marcus Luttrell, a Navy SEAL who single