The ONE Thing by Gary Keller [Actionable Summary]

This is a comprehensive summary of the book The ONE Thing by Gary Keller. Covering the key ideas and proposing practical ways for achieving what’s mentioned in the text. Written by book fanatic and online librarian Ivaylo Durmonski.

Worksheet: Download the interactive sheet for taking notes.

The Book In Three Or More Sentences:

The ONE Thing introduces a counterintuitive philosophy about succeeding in life – going small and focusing one doing only ONE thing. Gary Keller explains in great detail why you should shorten your to-do list. Actually, to get rid of your to-do list and make it do-only-one-thing list. Along with that, the book will force you to answer some no so common questions which will potentially help you find what’s most important for you in your life.

The Core Idea:

Contrary to what we think, we don’t need to involve ourselves with thousands of things to achieve the success we’re aiming for. We only need to do one thing. So, your first task in life should be to find that one thing, which when you repeatedly do, every-single-day, will help you achieve your goal(s) in life.


  • Don’t do anything until you know what’s your one thing in life.
  • Ignore everything else and focus all of your efforts on the one thing that is vital for your success.
  • Everything good in life happens over a long period of time.

5 Key Lessons from The ONE Thing:

Lesson #1: Go Small

“Going small” is a technique that will teach you to ignore all the things you could do and do only what you should do. Sounds confusing? Let me rephrase:

We all have the same number of hours in a day, right? But why do some people seem to get so much more done than others? Because they go small. They ignore the “need to do” and the “have to do” and execute only on the thing that is vital for their success – their one thing.

For instance, if you want to write a book, you can do all sort of things to prepare for your future book launch: Think about the cover; Which publisher to pick; How many pages to write; Whether or not to include pictures and all sort of other insignificant, at that point, details. Even though these things will be required at a certain stage, doing them now won’t help you publish a book, only writing will. So, by recognizing that not all things matter equally, you need to stop for a moment and find out what matters most for you – in this example it will be writing.

In every endeavor, there is always only one task which is extremely important for the success of the whole project. Focusing your time and energy on this sole task will help you move forward faster. Going small and working on your one thing works because it has only one purpose – to help you complete your project.

So, it all boils down to this: Go small. Don’t try to do everything. Find the most important task at the moment and focus all of your time and energy there.

Lesson #2: Good Things Happen Over Time

The aftermath of doing the most important thing repeatedly over time is a pure success. The keyword here is over time.

Kind of a bummer. I know. After all, we live in times where immediate results are put on a pedestal.

Your order gets delayed with an hour and you bombard the delivery firm with negative reviews and threatening tweets. But it is what it is. If you want to achieve something, you need to be a bit more patient and understand that good things happen over time.

As the author explains in the book, “When you see someone who has a lot of knowledge, they learned it over time. When you see someone who has a lot of skills, they developed them over time. When you see someone who has done a lot, they accomplished it over time. When you see someone who has a lot of money, they earned it over time.”

The best thing you can do is to start today. Now. At this moment. If you start pursuing your dream life today, you will be one step closer tomorrow.

Success happens sequentially. Doing one thing repeatedly over a long period of time.

Lesson #3: Don’t Know What’s Your One Thing? Think About The Most Impactful Thing You Can Do

If today your company doesn’t know what its ONE Thing is, then the company’s ONE Thing is to find out.” Gary Keller

Finding your one thing is like finding meaning in life. We know it’s important but it’s damn hard to figure out what we actually want to achieve. If that’s the case with you, don’t worry. You’re not alone. There are millions of people struggling to find the answer to this profound question.

To assist us, Gary Keller shares the story of Bill Gates, the founder of Microsoft. He decided to put his wealth to work making a difference in the world after he retired. But since he can’t cure all diseases, even though he is quite wealthy, he decided to do one thing – focus on vaccines. Here’s how he explained his decisions: “We had to choose what the most impactful thing to give would be… The magic tool of health intervention is vaccines.” He asked himself, “Where’s the place I can have the biggest impact with my money?”

You can copy this approach in your quest.

Even though thanks to technology and innovation the available opportunities to spend our time and effort seem endless, doing fewer things actually makes us feel better.

The question you need to ask yourself if you’re not sure where you should focus your time is this: “What’s the one thing I can do that would have the biggest positive impact on others?”

As the quote above suggests, if you still don’t know what your one thing is, your one thing for the moment is finding out. Don’t do anything else till you know for sure.

Lesson #4: There Are Six Lies Standing Between You And Success

The author presents six lies we often tell ourselves which steer us towards the wrong way.

Here they are in short:

  1. Everything matters equally: When everything feels urgent and important, everything seems equal. We jump from one task to another but this doesn’t actually help us move forward. You need to understand that not everything matters equally.
  2. Multitasking: Multitasking is a lie. By trying to do two things at once, you’re not doing either of them good.
  3. A disciplined life: Thinking you should be disciplined all the time is not possible. You just have to be discipline long enough to make doing your one thing a habit.
  4. Willpower is always on will-call: Think of willpower like the power bar on your cell phone. Every morning you start out with a full charge. As the day progresses, the bar gets lower. Meaning, willpower has a limited battery life, don’t beat yourself up when you don’t feel focused. Simply take a moment to recharge.
  5. A balanced life: Balanced living and Santa are alike – they both don’t exist. Try balancing your life when you have 3 kids, a full-time job and a desire to run a side hustle. So what do you do? Counterbalance. Some days you’ll spend more time with your family others more time on your business.
  6. Big is bad: Dreaming big is not bad, it’s necessary. It might sound cliché-ish, but thinking big is essential for reaching extraordinary results.

Don’t let small thinking cut your life down to size. Think big, aim high, act bold. And see just how big you can blow up your life.” Gary Keller

Lesson #5: Make Sure You Can Live With What You Will Inevitably Lose

Being good at doing one thing always means that you’ll suck at something else. Just make sure that other thing is not something you cherish – like your family.

Let me illustrate it this way for you: Let’s say you’re driving your car on the road. At some point, you come to a fork in the road. If you take road number one, you get to become a world-class baseball player. However, all the things that are the end of road number two are slowly fading away. Getting to them will mean losing everything you’ve achieved through road number 1.

So, the conclusion here is the following: To achieve an extraordinary result at one thing, you must settle with average outcomes at something else. Choose what matters most and give it all the time it demands. This, however, will mean that you have to compromise.

Sometimes you’ll have to choose work over family and the opposite. Such decisions are always hard but that’s the only way you can achieve the desired success.

Actionable Notes:

  • Short to-dos: Filled calendars and overwhelming to-do lists lead only to stress and anxiety. A lot of people think that having too much to do means that they are productive. It’s quite the opposite. Trim your to-do list and focus on doing only one thing – this way you’ll achieve much more.
  • Time block: We all have a limited amount of time at our disposal. A way to get more done is by blocking a chunk of time and then protect it fiercely. Don’t allow anything to interrupt your time block.
  • Discover your Big Why: Discover your purpose by asking yourself what drives you. What’s the thing that gets you up in the morning and keeps you going when you’re tired and worn down? The author refers to this as the “Big Why.” It’s what excites you. It’s why you’re doing what you’re doing.

Commentary And My Personal Takeaway

While most productivity authors try to help you do a lot of things simultaneously, Gary Keller explains why you should focus only on doing one thing.

Although the text is full of clichés and you-can-do-it phrases, The ONE Thing is an overall good read about how to manage your time well and how to find your most important thing in life.

My biggest take from the book is that not everything deserves equal time and that finding your one thing (obviously) is essential if you want to get better in life.

So, if you don’t know yet, think, and finally choose the most impactful thing you can do to help other people around. Once you know, focus your time on this ONE thing.

Notable Quotes:

When you’re supposed to be working, work, and when you’re supposed to be playing, play.” Gary Keller

Based on where I am right now, what’s the ONE Thing I need to do this week to stay on track for my monthly goal and for my monthly goal to be on track for my annual goal?” Gary Keller

When you try please everyone, the one person you absolutely won’t please is yourself.” Gary Keller

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

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