Every kindness I received, small or big, convinced me that there could never be enough of it in our world. To be kind is to respond with sensitivity and human warmth to the hopes and needs of others. Even the briefest touch of kindness can lighten a heavy heart.

My last piece of advice is the one I could have used the most. It took me a long time to learn. And it is this: You are not a slacker if you cut yourself some slack. When I was your age, I didn't believe in vacations. I didn't believe in weekends. I pushed everyone around me to work very long hours. In the early days of Microsoft, my office overlooked the parking lot—and I would keep track of who was leaving early and staying late. But as I got older—and especially once I became a father—I realized there is more to life than work. Don't wait as long as I did to learn this lesson.

Scientists are people who are curious and want to pursue knowledge and pursue truth, and this still remains the most timeless and priceless value of a scientific career. My advice to an early-career scientist is to remain true to your passion and curiosity and that sense of mission to discover knowledge and uncover innovation. It's also very important to be using the tools of the moment, of the century. There are a lot of new tools to uplevel our own scientific research and scientific quest.

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.

It is that you know that you are standing out in this crowd because you are being carried on the shoulders of others. You know, you may have the capacity to articulate their aspirations. That is maybe something special you might have. But what is a leader without followers? I mean you would have all of these interviews and people will not — would not necessarily want to follow. No, I am a great believer in the fact that everything is corporate. Everything is corporate and you — as a leader you are one who can coax the best out of others.

I sent off the letter. I probably made a technical mistake by giving it to a journalist before hearing from the Prime Minister because this journalist was working for a Sunday newspaper and gave it enormous press, and I think quite rightly the Prime Minister was annoyed that I had not given him the opportunity but never mind.

I stopped being a teacher when the South African Government introduced a deliberately inferior education for blacks called Bantu education, and I felt I wasn’t ready to collaborate with this apology for an educational system. Our children, the 1976 kids who revolted against apartheid in Soweto, called it “gutter education,” and it was gutter education. I left teaching. Of course, I didn’t have too many option, and mercifully, the Bishop of Johannesburg at that time accepted me for training for the priesthood. So I came to the priesthood, as it were, by default.

There will always be so many who might say, “Ah, he’s a politician masquerading as an archbishop.” Politics is so all-pervasive, and in my theology, obviously, all of life belongs to God, and you don’t have compartments, this is your economic life, this is your political life, this is your religious life. Religion encompasses all of those. But yes, I wouldn’t myself have said I was setting out to be a political animal.

One moment, Nelson Mandela is in jail, and the next moment, he is walking, a free man. One moment, we are shackled as the oppressed of apartheid; the next, we are voting for the very first time. I was 63 when I voted for the first time in my life in the country of my birth. Nelson Mandela was 76 years of age. But it happened, it happened. It happened partly because the international community supported us. People prayed for us. People demonstrated on our behalf, especially young people. Students at universities and college campuses used to sit out in the baking sunshine to force their institutions to divest and the miracle happened. We became free because we were helped and we want to say a big “thank you” to the world. And, you can become free nonviolently.

Ultimately, it’s a man who was teaching us English Literature in what we call matricula, the last 2 years of high school. He really was quite extraordinary. When he spoke of a Shakespearean play, you almost thought that he grew up with Shakespeare! He was very good, yes. A black guy who was fantastic and gave us a deep love for literature.