From Ray Dalio’s “Principles” (p.21):
In summary, I believe that you can probably get what you want out of life if you can suspend your ego and take a no-excuses approach to achieving your goals with open-mindedness, determination, and courage, especially if you rely on the help of people who are strong in areas that you are weak.
If I had to pick just one quality that those who make the right choices have, it is character. Character is the ability to get one’s self to do the difficult things that produce the desired results. In other words, I believe that for the most part, achieving success—whatever that is for you—is mostly a matter of personal choice and that, initially, making the right choices can be difficult. However, because of the law of nature that pushing your boundaries will make you stronger, which will lead to improved results that will motivate you, the more you operate in your “stretch zone,” the more you adapt and the less character it takes to operate at the higher level of performance. So, if you don’t let up on yourself, i.e., if you operate with the same level of “pain,” you will naturally evolve at an accelerating pace. Because I believe this, I believe that whether or not I achieve my goals is a test of what I am made of. It is a game that I play, but this game is for real.