Eric Carle 's memorable children's book has been adopted by nutritionists, preachers, ecologists, actors, satirists, teachers and psychotherapists, and is still a favourite among parents and children, maintaining an unshakeable position in the bestseller list. It was recently cited by George W Bush as the most influential book he had ever read and it has been described as a profound philosophical text to rival Kahlil Gibran 's The Prophet. Poet John Hegley investigates the phenomenon. Producer Kate Taylor