I am not dull enough to suppose that because you are young，gifted and well-educated，you have never known hardship or heartache.Talent and intelligence never yet inoculated anyone against the caprice of the Fates，and I do not for a moment suppose that everyone here has enjoyed an existence of unruffled privilege and contentment.However，the fact that you are graduating from Harvard suggests that you are not very well-acquainted with failure.You might be driven by a fear of failure quite as much as a desire for success.Indeed，your conception of failure might not be too far from the average person’s idea of success，so high have you already flown academically.
Ultimately，we all have to decide for ourselves what constitutes failure，but the world is quite eager to give you a set of criteria if you let it.So I think it fair to say that by any conventional measure，a mere seven years after my graduation day，I had failed on an epic scale.An exceptionally short-lived marriage had imploded，and I was jobless，a lone parent，and as poor as it is possible to be in modern Britain，without being homeless.The fears my parents had had for me，and that I had had for myself，had both come to pass，and by every usual standard，I was the biggest failure I knew.
Now，I am not going to stand here and tell you that failure is fun.That period of my life was a dark one，and I had no idea that there was going to be what the press has since represented as a kind of fairy tale resolution.I had no idea how far the tunnel extended，and for a long time，any light at the end of it was a hope rather than a reality.
So why do I talk about the benefits of failure？Simply because failure meant a stripping away of the inessential.I stopped pretending to myself that I was anything other than what I was，and began to direct all my energy into finishing the only work that mattered to me.Had I really succeeded at anything else，I might never have found the determination to succeed in the one arena I believed I truly belonged.I was set free，because my greatest fear had been realized，and I was still alive，and I still had a daughter whom I adored，and I had an old typewriter and a big idea.And so rock bottom became the solid foundation on which I rebuilt my life.
You might never fail on the scale I did，but some failure in life is inevitable.It is impossible to live without failing at something，unless you live so cautiously that you might as well not have lived at all-in which case，you fail by default.
Failure gave me an inner security that I had never attained by passing examinations.Failure taught me things about myself that I could have learned no other way.I discovered that I had a strong will，and more discipline than I had suspected；I also found out that I had friends whose value was truly above the price of rubies.
The knowledge that you have emerged wiser and stronger from setbacks means that you are，ever after，secure in your ability to survive.You will never truly know yourself，or the strength of your relationships，until both have been tested by adversity.Such knowledge is a true gift，for all that it is painfully won，and it has been worth more to me than any qualification I ever earned.
So given a Time Turner，I would tell my 21-year-old self that personal happiness lies in knowing that life is not a check-list of acquisition or achievement.Your qualifications，your CV，are not your life，though you will meet many people of my age and older who confuse the two.Life is difficult，and complicated，and beyond anyone‘s total control and the humility to know that will enable you to survive its vicissitudes.
You might think that I chose my second theme，the importance of imagination，because of the part it played in rebuilding my life，but that is not wholly so.Though I will defend the value of bedtime stories to my last gasp，I have learned to value imagination in a much broader sense.Imagination is not only the uniquely human capacity to envision that which is not，and therefore the fount of all invention and innovation.In its arguably most transformative and revelatory capacity，it is the power that enables us to empathize with humans whose experiences we have never shared.
One of the greatest formative experiences of my life preceded Harry Potter，though it informed much of what I subsequently wrote in those books.This revelation came in the form of one of my earliest day jobs.Though I was sloping off to write stories during my lunch hours，I paid the rent in my early 20s by working at the African research department at Amnesty International’s headquarters in London.
There in my little office I read hastily scribbled letters smuggled out of totalitarian regimes by men and women who were risking imprisonment to inform the outside world of what was happening to them.I saw photographs of those who had disappeared without trace，sent to Amnesty by their desperate families and friends.I read the testimony of torture victims and saw pictures of their injuries.I opened handwritten，eye-witness accounts of summary trials and executions，of kidnappings and rapes.
Many of my co-workers were ex-political prisoners，people who had been displaced from their homes，or fled into exile，because they had the temerity to think independently of their government.Visitors to our office included those who had come to give information，or to try and find out what had happened to those who they had left behind.
I shall never forget the African torture victim，a young man no older than I was at the time，who had become mentally ill after all he had endured in his homeland.He trembled uncontrollably as he spoke into a video camera about the brutality inflicted upon him.He was a foot taller than I was，and seemed as fragile as a child.I was given the job of escorting him to the Underground Station afterwards，and this man whose life had been shattered by cruelty took my hand with exquisite courtesy，and wished me future happiness.