According to a different source, this question refers to the text The Pact. In this book, we learn the story of three boys who make a pact when they are young. They promise to work hard and eventually become doctors.
In this part of the story, one of the kids (now a man called Dr. Davis) recognizes Don Moses as a man who he used to know when little. However, Don Moses is now dead, after many difficulties and obstacles throughout his life.
While Don Moses was surrounded by violence and poverty, Dr. Davis was making a good salary, living in a stable way, and fulfilling his dreams. Their lives turned out to be very different from each other. Dr. Davis believes that the critical element that changed his life for the better was the pact he made with his friends. This encouraged him to be more hardworking, but also to increase his confidence and believe anything was possible.