If everyone is having the same amount of time a day , how comes it that some people achieve more , have more and do more than others ?  This book is likely to be the answer to your question . 
We all hope that our efforts and hardwork reach us to the greatest possible results, but unfortunately the reality is that most of us do not achieve the great desired results for different reasons.  
One of the most important reasons is that we distract our efforts , focus and time on many things . Since the doors to the world have been wide open and the view that's shown is astounding . As thrilling this can be , it can be accurately overwhelming . The choices and opportunities seem endless so we end up doing too much and accomplishing too little .

In their book 'The ONE Thing' , Gary Keller and Jay Papazan discuss the main idea of which that extraordinary results are directly determined by how much narrow you can make your focus . They represent their main concept which they call 'going small' which is based on the thought of ignoring all the things you could do and doing what you should do , recongnizing that not all things matter equally and finding the thing that matters most , your ONE thing . 

" If you chase two rabbits , you will not catch either one " .
Most of us think that multitasking is something effective and useful to do , and some have gone so far by believing it's something they should do and be proud of it and considering it as a skill that should be adopted as way of life while it's a way of LIE . Because doing two things at a time is to do neither . When you try to do things at the same time you either can't or won't do either well .when we do two things or more at once we're simply dividing up our focus and dumbing down all of the outcomes in the process. Haunting and doing dozens of things is a poor substitute for doing one thing that's meaningful . Not everything matters equally and reaching the desired results isn't determined by how many things you do as much as by how good and effective the way you get them done with . 
We may have seen people who are both multitaskers and successful , how fair the ONE thing thought can be? The book essentially claims that success is built sequentially not simultaneously . It's one thing at a time .
The authors propose that there are six lies or illusions that our believing in them is what actually prevents us from achieving big results : 
  1. Everything matters equally
  2. Multitasking
  3. A disciplined life
  4. Willpower is always on will-call
  5. A balanced life
  6. Big is bad

When we are tempted to focus on more than one priority at a time , the book suggests we should ask a question . The question that stands at the heart of the book is the focusing question : 
"what's the one thing you can do such that by doing it everything else will be easier or unnecessary ?" 
This question should be mainly asked when we feel anxious , overwhelmed, and when we're getting distracted . This question shapes our thinking in many ways , it reminds us that if we want to be successful and achieve what we want there is no such thing as having priorities , there is only  one priority , one most important thing in this moment in time . Oftentimes , we think things are equally important because we have that feeling of overwhelm that makes everything seem good and we mistake that goodness for importance . 
The focus question causes us to pause and break the illusion that just because something feels urgent and good doesn't mean it's equally as important as everything else , when we ask this question one thing will rise to the surface allowing everything else to fade away .
Gary says your purpose is simply the one thing you want your life to be about more than any other , it's what you want to be remembered for at the end of your career and at the end of your life .
To paraphrase Gary Keller :
 " the key to success isn't doing more , it's doing a few things really well " . 

Some will misunderstand what the thought the book is meant to convey , for , by determining and focusing on your ONE thing doesn't mean you should ignore everything else . Your family and your health are on priority all the time . There are things that can't be compensated and ignoring them will cost you much more than the rewards you may achieve . 

The book was really helpful , a must read for everyone who dreams big and wants to achieve big results , it clearly makes the path one should take to a succeful life .