But whenever you do find something — maybe it’s not as passionate for you as dog mushing has been for me — but the fact that you have any interest, that is what you should go with.

And the most fulfilled, centered, grounded, happy people I know are people who made the choice to be part of an effort to actually make the world a better place. ... I would say, to me, the path of least regrets is to at least make a short-term commitment to say, “Let me work to make a real difference in the world.” The worst that could happen is you decide to move into something else later, but you’ll always take with you what you’ve given and what you’ve gained through that experience.

So I urge my sisters, and my brothers, not to be afraid. Be not afraid to denounce injustice, though you may be outnumbered. Be not afraid to seek peace, even if your voice may be small. Be not afraid to demand peace.

The advice that I would give is try to find something that you like. Try to devote your energies to being very good at it. Try to achieve excellence. Don’t necessarily have as a goal success or getting prizes or whatever, but just doing very good work. And work hard. Keep working at it. Be patient. Realize that you don’t always see the benefits of what you’re doing, short-term. But in the end, the activities that I do, for example, scientific research, can be extremely rewarding. It’s really a very fascinating career.

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 realised, 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.

The friends with whom I sat on graduation day have been my friends for life. They are my children’s godparents, the people to whom I’ve been able to turn in times of trouble, people who have been kind enough not to sue me when I took their names for Death Eaters.