It allows you to focus your mind on what's at hand, not a distant victory whether it's the money that's going to be in your account or an award that you may or may not get someday. Since it un-clutters your mind, you can concentrate on the task at hand. It absolves you of the result, good or bad bestowing upon you a sense of peace and calm settle in you as you go about doing your duty, whatever that maybe.
There's a similar story in a Zen koan. An impatient student keen on learning kendo, a Japanese martial art(way of the Sword), approaches the sensei and asks him to teach the art of kendo. The master says it will take ten years. The student, appalled, says, 'But master, I have to learn it in five years'. 'Oh?' says the master, 'in that case, it will take twenty years'.
The lesson is: focus on what you have to do and the rest will take care of itself. In the case of the student, effort and single-minded attention would have ensured that he became adept at the art in ten years or less, but with his mind on the result, it was obviously going be delayed. The more impatient you are, the longer it will take.
Which somehow ties back to Stephen King's 'writers write' piece of advice. It doesn't matter if your book is published or not; whether you have a million readers or five. All that matters is that you sit at the computer and write. Because, like he says: “Writing isn't about making money, getting famous, getting dates, getting laid, or making friends. In the end, it's about enriching the lives of those who will read your work, and enriching your own life, as well. It's about getting up, getting well, and getting over. Getting happy, okay? Getting happy.”
It doesn't have to be stories all the time. You can take a break between your novels and story writing schedule by writing blogs. Even if you write a bestseller, what next? Are you going to stop? Is that the best you got, to quote Ali (apparently that was how he taunted his opponents in the ring)? Not all bestsellers are great. Again, going back to King, he hates Snowfall in the cedar type stories; Tom Robbins loathes 'Fifty shades of grey'. So to write a decent book, you have to keep writing, and if you make it to the bestseller list, great, but that's just the beginning. As they said when I was learning Aikido very briefly, 'a black belt is not the end, it's the beginning'.