I had set my mind on winning the 1500-meter gold medal in Helsinki in 1952. ... And, it all came disastrously wrong when I came fourth instead of winning. ... Instead of retiring in order to devote myself to medicine, I decided to go on for another two years while I was still a student, working clinically in London, and I did that.

That's a real challenge and a real issue. Reading the statistics, they had a ranking of quarterbacks, and the statistic was the percentage of a touchdown drive after an interception. To me, that is a telling statistic. The guys that have a high percentage are the guys that have short memories. They talk about having amnesia as a quarterback. You better move along from it. It is hard to say you forget about it, because you want to learn from it. You want to address it. You can't just say it never happened.

To launch Canva, we needed investment and a tech team. Finding the right people for both took two years but there is always a lot of rejection for entrepreneurs in their early days. But every time we got a hard question or a reason why people wouldn't invest, we stayed focused on what we could change. I revised our pitch deck after every meeting, more than 100 times in one year, to answer the questions or fix the reason for rejection from the last time. You just have to keep going. The normal thing to do after your 100th, 80th or even 20th ‘no’ would be to stop, but you just have to persevere.

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.

The task of finally making a decision to hang up my racquet felt a lot more difficult than winning seven matches in a row in the Australian heat. It took me several agonizing months to finally come to the decision that my chronic injuries will never again let me be the tennis player that I can be. Walking away from the sport, effective immediately, is the right decision for me and my family.

After four knee surgeries and hundreds of shots injected into my knee weekly to alleviate swelling and pain, my body is begging me to stop the pounding. My previous three surgeries were on my right knee. My most recent knee surgery took place this July and was on my left knee.