In the Introduction, Greene explores the concept of ultimate power and intelligence that leads to extraordinary achievements in various fields. Greene identifies this power as mastery, a sensation characterized by a deep command of reality, other people, and oneself. He emphasizes that mastery is not a result of innate talent or luck but rather a process accessible to all individuals.

Greene refers to the three distinct phases of achieving mastery: apprenticeship, creative-active, and mastery. In the apprenticeship phase, individuals start as outsiders, where they focus on learning the basics of their field through observation and practice. They gradually gain fluency and confidence, as they transition to practitioners who experiment with their own ideas. Finally, with years of dedication and focus, individuals reach mastery, where they possess an in-depth understanding of their domain, which enables them to make rapid and creative decisions.

Throughout the Introduction, Greene debunks myths surrounding mastery, such as the notion of genius being inaccessible or reliant on external factors. Instead, he argues that mastery is within reach for anyone willing to undergo the rigorous process of learning, practice, and continuous improvement. Greene draws on examples from history, including Leonardo da Vinci, Napoleon Bonaparte, and Thomas Edison, to illustrate how mastery manifests in various fields and its transformative impact on society.