How has a failure, or apparent failure, set you up for later success? Do you have a favourite failure?

I feel that because I challenge myself so often, sometimes I will fail. This is, to me, the essence of competition — that there will be both winners and losers. But I have great faith in myself that I will turn this loss into something positive.

No one has a 5.0 in real life. In fact, when you finish school, the whole notion of a GPA just goes away. When you're in school, every little mistake is a permanent crack in your windshield. But in the real world, if you're not swerving around and hitting the guard rails every now and then, you're not going fast enough. Your biggest risk isn't failing, it's getting too comfortable.

As hard as it's been to come to this decision, I am at peace with it. I have no regrets. I was not supposed to be here in the first place, remember? Not many people believed in my talent and my abilities, yet I found a way to persevere, to prove them (and sometimes myself!) wrong.

But after one year of medical school I fled. I realized I would be a very unhappy doctor and I really did not want to be responsible for the inadvertent death of my patients. Leaving medical school was a very unusual decision, especially in Nigeria where it is very difficult to get into medical school. Later, people told me that it had been very courageous of me, but I did not feel courageous at all. What I felt then was not courage but a desire to make an effort. To try.

It was like switching out the engines mid-flight. I remember the day we turned on this free service, had we probably gone on for about six more months, I think we might have died as a company. That was a defining moment and that was as late as 2013. I think every great company has at least three near-death experiences.

When I lost that 100m final I spiralled. I went quite aggressive. It is an Adam I don't really recognise.