As you grow up, you are told to renounce most of the hopes and dreams of your youth, and resign yourself to a life that will be a pale dilution of the adventurous, important and enjoyable life you once expected. But who wants to do any of that? No wonder we live in a culture of rampant immaturity, when maturity looks so boring. The moral philosopher discusses childhood, adolescence, sex, and culture, and asks how the idea of travel can help us build a model of maturity that makes growing up a good option and leaves space in our culture for grown-ups. Chaired by Sarah Crompton.