• Toby Sinclair

Book Summary: The ONE Thing by Gary Keller | Big Ideas and Quotes

Updated: Oct 4


The One Thing: The Surprisingly Simple Truth Behind Extraordinary Results

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“What’s the ONE Thing I can do, such that by doing it, everything else will be easier or unnecessary?”

10 Principles:


This summary of The One Thing by Gary Keller you will see how to put these principles into action:

  1. Create a domino effect in your life

  2. Avoid the Six Lies that limit success

  3. Self-Discipline is a myth

  4. Manage willpower like a renewable energy

  5. Lead an Unbalanced life

  6. Ask the Focusing Question

  7. Align Life to Purpose

  8. Visualize process not just the final outcome

  9. Learn how to focus

  10. Defeat the Four Thieves of productivity


Toby's Top Takeaways


As a professional coach, I'm always looking for new powerful questions. So as you can imagine I loved the central question to this book. I have now started using it as part of my weekly and daily goal-setting system.


In this summary of the one thing an aspect I'm a little sceptical about the domino metaphor. I do believe that small actions can lead to big results, however, it is often much less linear than falling dominos. Small changes can create exponential results in surprising ways.


My profession involves Coaching Product Managers so I really resonated with the "inability to say no". This is a big problem for many Product Managers so I'll be sharing with them the "Four Thieves of Productivity"


I hope this summary of the one thing will help bring focus to your life.

A longer summary of The One Thing:


1. Create a Domino Effect in your life:


“Every great change starts like falling dominoes.”—BJ Thornton

Getting extraordinary results is all about creating a domino effect in your life.


Knocking out a hundred tasks for whatever the reason is a poor substitute for doing even one task that’s meaningful. Find what can create a domino effect.


Research Evidence to back up the theory


2. Avoid the Six Lies that Limit Success:

  1. Everything Matters Equally

  2. Multitasking is productive

  3. Belief in Self-Discipline

  4. Willpower is always on-call

  5. A Balanced Life

  6. Big Is Bad


3. Self-Discipline is a Myth:

“It’s one of the most prevalent myths of our culture: self-discipline.”—Leo Babauta

Discipline doesn’t exist. What does is specific Habits performed consistently over time.


Good Habits create a Halo Effect (Megan Oaten and Ken Cheng)

  • One Positive Habit can lead to many positive side effects. Doing the most important thing regularly, everything else is easier.

You are what you repeatedly do


“People do not decide their futures, they decide their habits and their habits decide their futures.”—F. M. Alexander


4. Manage Willpower like a Renewable Energy


Will power is a limited but renewable resource.

Behaviour won't change when Willpower is Low. You'll do what's automatic.


Be aware of what depletes willpower:

  • Filtering distractions

  • Resisting temptation

  • Suppressing emotion

  • Restraining aggression

  • Trying to impress others

  • Coping with fear

  • Doing something you don’t enjoy

5. Lead an Unbalanced life


Change happens at the extremes, not in balance.


All priorities cannot matter equally. When you focus on ONE THING you may feel unbalanced.

“To achieve an extraordinary result you must choose what matters most and give it all the time it demands. This requires getting extremely out of balance in relation to all other work issues. An extraordinary life is a counterbalancing act.” - Gary Keller

Success = being appropriate in the moments of your life.


“Focus is a matter of deciding what things you’re not going to do.”—John Carmack

“Going small” is ignoring all the things you could do and doing what you should do. It’s recognizing that not all things matter equally and finding the things that matter most. It’s a tighter way to connect what you do with what you want. It’s realizing that extraordinary results are directly determined by how narrow you can make your focus.


A Great Metaphor for Balance:

“Imagine life is a game in which you are juggling five balls. The balls are called work, family, health, friends, and integrity. And you’re keeping all of them in the air. But one day you finally come to understand that work is a rubber ball. If you drop it, it will bounce back. The other four balls—family, health, friends, integrity—are made of glass. If you drop one of these, it will be irrevocably scuffed, nicked, perhaps even shattered.” - James Patterson

6. Ask the Focusing Question


“What’s the ONE Thing I can do, such that by doing it, everything else will be easier or unnecessary?”

Ask the wrong question, get the wrong answer. Ask the right question, get the right answer. Ask the most powerful question possible, and the answer can be life-altering.


7. Align Life to Purpose


Purpose = The ONE Thing you want your life to be about more than any other.


Gary Keller's purpose is to..... help people live their greatest life possible through my teaching, coaching, and writing.


A metaphor for Purpose:

“Would you tell me, please, which way I ought to go from here?” “That depends a good deal on where you want to get to,” said the Cat. “I don’t much care where—” said Alice. “Then it doesn’t matter which way you go,” said the Cat.

Origin of Priority:

To be precise, the word is priority—not priorities—and it originated in the 14th century from the Latin prior, meaning “first.” If something mattered the most it was a “priority.” Curiously, priority remained unpluralized until around the 20th century, when the world apparently demoted it to mean generally “something that matters” and the plural “priorities” appeared.
“I cannot believe that the purpose of life is to be happy. I think the purpose of life is to be useful, to be responsible, to be compassionate. It is, above all, to matter, to count, to stand for something, to have made some difference that you lived at all.” Leo Rosten

8. Visualize the Process NOT just final outcome

In three separate studies, psychologists observed 262 students to see the impact of visualization on outcomes. The students were asked to visualize in one of two ways: Those in one group were told to visualize the outcome (like getting an “A” on an exam) and the others were asked to visualize the process needed to achieve the desired outcome (like all of the study sessions needed to earn that “A” on the exam). In the end, students who visualized the process performed better across the board.

9. Learn how to focus


Researchers estimate that office workers are interrupted every 11 minutes and then spend almost a third of their day recovering from these distractions.


When everything feels urgent and important, everything seems equal. We become active and busy, but this doesn’t actually move us any closer to success. Activity is often unrelated to productivity, and busyness rarely takes care of business.

“The things which are most important don’t always scream the loudest.”—Bob Hawke

Ref: The Good Samaritan Experiment

  1. These students were recruited and divided into two groups to see what factors influenced whether or not they would help a stranger in distress. Some were told they were going to prepare a talk about seminary jobs; the others, that they were going to give a talk about the Parable of the Good Samaritan, a Biblical story about helping people in need. Within each group, some were told they were late and had to hurry to their destination, while others were told they could take their time. What the students didn’t know was that researchers had planted a man along the way—slumped on the ground, coughing, apparently in distress. In the end, fewer than half the students stopped to help. But the deciding factor wasn’t the task—it was time. Ninety percent of the students who were rushed failed to stop and render aid to the stranger. Some actually stepped over him in their hurry to get where they were supposed to go. It didn’t seem to matter that half of them were on their way to deliver a talk on helping others!


10. Defeat the Four Thieves of Productivity

  1. Inability to Say “No”

  2. Fear of Chaos

  3. Poor Health Habits

  4. Environment Doesn’t Support Your Goals

Inability to Say “No”


When you say yes to something, it’s imperative that you understand what you’re saying no to.


Reasons we struggle to say no:

  1. We want to be helpful

  2. We don’t want to be hurtful

  3. We want to be caring and considerate

  4. We don’t want to seem callous and cold

  5. Being needed is incredibly satisfying, and helping others can be deeply fulfilling.

“You can say no with respect, you can say no promptly, and you can say no with a lead to someone who might say yes. But just saying yes because you can’t bear the short-term pain of saying no is not going to help you do the work.” Seth Godin

Fear of Chaos

When you strive for greatness, chaos is guaranteed to show up. - Gary Keller

One of the greatest thieves of productivity is the unwillingness to allow for chaos


When we focus, clutter automatically takes up residence around us. Untidiness. Unrest. Disarray. Disorder.


Focusing on ONE Thing has a guaranteed consequence: other things don’t get done.


Your environment must match your goals


The people surrounding you and your physical surroundings must support your goals.

  • 2007 study on obesity revealed that if one of your close friends becomes obese, you’re 57 percent more likely to do the same. Why? The people we see tend to set our standard for what’s appropriate.


©2020 by Toby Sinclair.