For more than twenty years, from war zones to the seats of political power, Katya Adler has interviewed, observed, told people's stories. And she's always been fascinated by what makes people tick - their personality. Can we change or fake it? In the first of three programmes, Katya meets Olympic athlete and vice-president of Headway, James Cracknell, who suffered an injury to the brain a decade ago which caused some of his personality traits to change. Katya and James discuss the impact of the injury on James's personality, the extent to which personality is observed by people around us and how our personalities can evolve. Producer: Camellia Sinclair