To accomplishing great things in your life one must cease to dwell on the negative things in your past. Carefully assess your present strengths, successes, and achievements. Dwell on those positive events in your life, and quit limiting your potential by constantly thinking about what you have done poorly. Alice and the Mad Hatter in Wonderland had a conversation that illustrates this concept:
Alice: Where I come from, people study what they are not good at in order to be able to do what they are good at.
Mad Hatter: We only go around in circles in Wonderland, but we always end up where we started. Would you mind explaining yourself?
Alice: Well, grown-ups tell us to find out what we did wrong, and never do it again
Mad Hatter: That's odd! It seems to me that in order to find out about something, you have to study it. And when you study it, you should become better at it. Why should you want to become better at something and then never do it again? But please continue.
Alice: Nobody ever tells us to study the right things we do. We're only supposed to learn from the wrong things. But we are permitted to study the right things other people do. And sometimes we're even told to copy them.
Mad Hatter: That's cheating!
Alice: You're quite right, Mr. Hatter. I do live in a topsy-turvy world. It seems like I have to do something wrong first, in order to learn from what not to do. And then, by not doing what I'm not supposed to do, perhaps I'll be right. But I'd rather be right the first time, wouldn't you?