"Focus on the journey" is an old idea that can be found in most ancient philosophies. In the Bhagavad Gita, Krishna exhorts Arjuna to focus on his action, not on the fruits:
"You have a right to perform your prescribed duties, but you are not entitled to the fruits of your actions. Never consider yourself to be the cause of the results of your activities, nor be attached to inaction."
Seneca says something similar in on of his letters when he writes:
"Attalus philosophus dicere solebat iucundius esse amicum facere quam habere, quomodo artifici iucundius pingere est quam pinxisse" - The phylosopher Attalus used to say that making friends is as enjoyable than having them, just like for the painter, painting is more important than having painted.
More recently, Bill Walsh, the famous 49ers coach, used to say that "the score takes care of itself", referring to the importance of daily practice and attitude in achieving results in the field when game-time came.
I have always liked this way of thinking, to the point of making the Seneca one my motto. It is important however to understand it correctly. The right interpretation is about mental energy and focus. Once you have established your goal, all you have to do is making sure that you put in the right behaviour. That's the only variable you really control. Are you performing, day after day, week after week, the actions that are most likely to eventually lead to your goal? Or are you stressing about not being able to achieve it and looking for shortcuts?
Every writer knows that the only way to complete a book is to sit down in front of the blank paper or screen everyday and write. Putting in the hours is the only true way writing gets done. So does the football player. Come to practice, perform, live a healthy life, the score will take care of itself.
The wrong interpretation is to believe that process alone will tell you what to do. That you can apply a rational step-by-step process to define your goal and to live your life. In sports the goal is given. It's the championship, the super bowl, whatever your sport has. In life and business it is less clear. Our first step should be to define our goal, who do we want to be? what do we want to achieve? The next one is to understand what actions are needed to get there. Can you achieve your goal without putting in the right amount of hours? Can you do it without sleeping well, eating well, letting your mind wander around sometime? The right actions will ofter feel to have the least short term impact on the goal. That's the difficult part, to put the goal aside once we have defined it. To forget any form of short term thinking and optimisation.
Every day, do what you are supposed to do, and enjoy the ride.