Feedback
"People who fail to achieve their goals usually get stopped by frustration. They allow frustration to keep them from taking the necessary actions that would support them in achieving their desire. You get through this roadblock by plowing through frustration, taking each setback as feedback you can learn from, and pushing ahead. I doubt you'll find many successful people who have not experienced this. All successful people learn that success is buried on the other side of frustration."
Anthony Robbins