Horizon explores the secrets of what makes a long, healthy and happy life. It turns out that a time you can't remember - the nine months you spend in the womb - could h*e more lasting effects on you today than your lifestyle or genes. It is one of the most powerful and provocative new ideas in human science, and it was pioneered by a British scientist, Professor D*id Barker. His theory has inspired a field of study that is revealing how our time in the womb could affect your health, personality, and even the lives of your children.