I think fear and fear of the unknown and perceived failure is what holds people back. For me, I am more scared of complacency than having something not work out. I'd rather take a leap of faith and fall than stand on the edge forever.

My key message to her, as a nine-year-old, recently has been, “You don’t need to be friends with everyone, but you’re forced to respect everyone. And everyone doesn’t need to be friends with you, but everyone is forced to respect you.”

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.

My grandfather looked at me, and after a bit of silence, he gently and calmly said, “Jeff, one day you'll understand that it's harder to be kind than clever.”

I’ve been mortally opposed to the so-called life-and-death committees that were instituted. When there were many more patients that needed to be dialyzed, and not enough artificial kidneys available, you had the institution of the life-and-death committees. ... Depending on the answer to these questions, he could be dialyzed. Otherwise, he could go to hell. I’ve been mortally opposed to that. When I set up a dialysis center here with a grant from some government agency, I was forced to put in a life-and-death committee, but it never met.

When I was this young assistant at the University of Groningen my responsibility was for four beds, or rather the patients in four beds. That was all I had to do. And, one of these patients was a young man, 22 years old, who slowly and miserably died from renal failure. He became blind, he vomited, and it was a miserable death. And I, as a very, very young physician, had to tell his mother, in a black dress and a little white cap like the farmers have, that her only son was going to die. I couldn’t do a damn thing about it. So, I began to think, “If I could just every day remove as much urea as this boy creates, which is about 20 grams, then the boy could live.” Well, he died, but I began to work on that.

In my early years it was undoubtedly my father. My father was director of a sanatorium for pulmonary tuberculosis, and at that time there were no antibiotics, tuberculosis was a terrible disease. And, he and I would walk in the woods around that sanatorium and he would discuss his worries about his patients. And from him, I certainly inherited this extreme concern about the well-being of patients. I’ve seen him very happy when he succeeded after months and months of rest and other things to have these people go home cured. I’ve also seen him crying and desperate after trying for a long time and a patient did not get well, and went home to die.

No. You see immediately what your next task will be. I’ve been asked all kinds of silly questions, like “Aren’t you proud? Aren’t you this? Aren’t you that?” I have no time for that, because the next project is upon me.