My top 10 highlights from the book:

1. We worked as a small expedition unit, in teams of three, four, or five, but we moved with the power of 10 bulls and the heart of a hundred men.

2. Walking out on my career felt risky, but I was prepared to gamble everything for my ambition.

3. From an early age, I believed in the power of positive thinking.

4. On weekends, my daily routine involved running for hours at a time. I'd haul my ass around the streets with two or three Gurkha buddies; we operated in a relay system, where I was the only soldier prevented from taking a break. One guy would accompany me for six miles, leading me along at a strong pace. Once he completed his distance, another running partner took over, and together we'd go six more miles. This went on for hours, and left me physically and psychologically pummeled.

5. I always smiled my way through the mud.

6. I focused only on the 24 hours ahead. Today I will give 100 percent and survive, I thought at the beginning of each day. I'll worry about tomorrow when tomorrow comes.

7. It is important to keep the promises you make yourself. If I say that I'm going to run for an hour, I'll run for a full hour. If I plan to do 300 push-ups in a training session, I won't quit until I've done them all-because brushing off the effort means letting myself down, and I don't want to have to live with that. And neither should you.

8. Emotional control was only one of the many traits I'd need to possess to become elite.

9. It was important to adapt to an increased workload.

10. The adventure taught me an important lesson. Fear was never going to hold me back from pressing ahead with my plans. It established in me a mindset with zero doubts and zero tolerance for excuses.