I would be willing to bet that not one person out there hasn't had at least one big, huge learning experience in the form of what could otherwise be called a "mistake." A car accident that taught you to drive more carefully; unintentionally hurting someone's feelings which taught you to be more careful with your words; a close call with drinking or drugs that led you to make healthier choices for yourself; forgetting too many important appointments leading you to learning better calendaring skills.
The important factor in this is what you choose to do with it. You could choose to beat yourself up over hurting someone's feelings or forgetting too many appointments, or you could choose to learn from it and work to reduce those types of mistakes in the future.
The cool thing? You can even do this in retrospect. Do you have a mistake in your past that you're still holding a grudge about against yourself? Stop and look at it. Did you know it was a mistake when you were doing it? How has this mistake changed you as a person? If you hadn't made this mistake and learned from it, who might you be now without having learned that lesson?
Chances are, a lot of what's made you as awesome as you are today, was figuring out all the things that didn't make you feel so awesome before, and then working on it.
It occurs to me that this ties in with self-forgiveness... Topic for another day.