“Extraordinary results are directly determined by how narrow you can make your focus.”

Throughout his book, Keller emphasizes the importance of narrowing goals, whether short-term or long-term, large or small. His key concepts, including the ONE Thing and the Focusing Question, are intended to help readers develop goals that are specific and focused enough to help them achieve their purpose. The better readers can focus in this way, Keller implies, the more likely they are to achieve success. 

“Find the lead domino, and whack away at it until it falls.”

Another of Keller’s key points is the idea that success is built incrementally and cumulatively through many small decisions. He likens this to a series of dominoes knocking down many pieces—even larger and larger pieces—in succession. This symbolizes what readers can achieve through focused actions aligned with their purpose: By maintaining focus across actions and time, they can make a great impact. 

“The ONE Thing sits at the heart of success and is the starting point for achieving extraordinary results.”

It is no surprise that Keller titles his book The ONE Thing because the ONE Thing is its leading concept. No matter how much work you accomplish, if your actions are not aligned with your purpose, then success will elude you. However, constantly returning to the most important thing you can do right now (or this week, this year, in the next five years, etc.