President Faust, members of the Harvard Corporation and the Board of Overseers, members of the faculty, proud parents, and, above all, graduates. The first thing I would like to say is ‘thank you.’ Not only has Harvard given me an extraordinary honour, but the weeks of fear and nausea I have endured at the thought of giving this commencement address have made me lose weight. A win-win situation! Now all I have to do is take deep breaths, squint at the red banners and convince myself that I am at the world’s largest Gryffindor reunion. Delivering a commencement address is a great responsibility; or so I thought until I cast my mind back to my own graduation. The commencement speaker that day was the distinguished British philosopher Baroness Mary Warnock. Reflecting on her speech has helped me enormously in writing this one, because it turns out that I can’t remember a single word she said. This liberating discovery enables me to proceed without any fear that I might inadvertently influence you to abandon promising careers in business, the law or politics for the giddy delights of becoming a gay wizard. You see? If all you remember in years to come is the ‘gay wizard’ joke, I’ve come out ahead of Baroness Mary Warnock. Achievable goals: the first step to self improvement. Actually, I have wracked my mind and heart for what I ought to say to you today. I have asked myself what I wish I had known at my own graduation, and what important lessons I have learned in the 21 years that have expired between that day and this. I have come up with two answers. On this wonderful day when we are gathered together to celebrate your academic success, I have decided to talk to you about the benefits of failure. And as you stand on the threshold of what is sometimes called ‘real life’, I want to extol the crucial importance of imagination. These may seem quixotic or paradoxical