Book excerpt: By the time Jack was fifteen he was addicted to alcohol and prescription drugs, was hanging out with rock stars in LA and living a life that any teenager would aspire to. And then The Osbournes turned him into a global celebrity. But as much as Jack enjoyed his fame, underneath it all he was still an awkward teenager, using his sense of humour as a shield. And with fame and money came a greater access to drugs - his addictions took a firmer hold on him and his behaviour was soon out of control. In 21 Years Gone Jack writes with brutal frankness about his descent into addiction and the low point he reached when Sharon was diagnosed with cancer. Scared that his mum might die, Jack retreated further into his alcoholic shell, hating who he was, hating what he did. Every night he would get into bed and pray for God to take his life. When Sharon realised what was happening she told Jack he had to go to rehab - and slowly he turned his life around. Discovering a passion for extreme sports, he went from overweight and unfit to the lean young man he is today - courtesy of such adventures as running with the bulls in Pamplona, fighting a Thai martial arts expert known only as 'The Man' and scaling El Capitan, one of the world's toughest climbs. By turns funny, disarmingly honest and moving, 21 Years Gone is the amazing story of young man who has confronted his demons and defeated them.