Memory plays a big part in shaping our identity, but can we rely on what we recall about ourselves and about others? Mike Williams finds out how human memory works and why some memories flood back more easily than others. He also explores whether different senses trigger different types of memories. Mike speaks to memory experts Martin Conway, Elizabeth Loftus, Gisli Gudjonsson, Maria Larsson and Simon Chu. The reader is Roberto Pistolesi.(Photo: Image of a brain scan. Credit: AFP/Getty Images)