One of the Fortune articles in many years was a cover story called 'What It Takes to Be Great'. Geoff Colvin offered evidence that top performers in any field are not determined by their inborn talents. Greatness doesn’t come from DNA but from practice and perseverance honed over decades. And not just plain old hard work, like your grandmother might have advocated, but a very specific kind of work. The key is how you practice, how you analyze the results of your progress and learn from your mistakes, that enables you to achieve greatness.