Every publication is searching for the magic key to open up their interviewees, a set of questions which can persuade even the most defensive subjects to reveal their secrets, their deepest thoughts and their biggest regrets.We, at the Big Issue, found our key. It is our Letter To My Younger Self series. Only when we’re being honest with ourselves - rather than the public, or an interviewer - do we admit truths which we would normally avoid talking about.Over 18 years we have asked thousands of celebrities what they would tell their younger selves.