It seems that anyone famous can 'write' their autobiography these days, even if they've hardly lived (I put 'write' in quotes as I suspect many of these books are ghost-written). Currently in the UK shops are 'autobiographies' of such people as actress/pop singer Billie Piper, singer (?)/'celeb' Kerry Katona and comedian Peter Kay, none of whom is yet out of their 20s (AFAIK). No doubt their fans will lap them up though, or so the publishers hope.