So you feel like a failure? Like your whole life is just one mistake after the other? The truth is, we all feel that way, because that's what life is, really. One shortcoming after another. But there's good news in that.
A smart man follows advice when it's first given, but a wise man learns it from experience. And what is experience, but trial and error? If you are right the first time, then you know how to do something, but if you make the mistake, you learn twice as much; what to do, and what NOT to do.
Mistakes are a teacher's greatest aspect. I used to think that in order to help people, I had to be perfect myself, but I find that through my failures and my shortcomings, I can offer the best advice. I've learned that from the people who've taught me as well. My parents aren't perfect, nor are they gallant military folk or 'heroes' by the modern sense of the word, but its through their humbleness that they've taught me some of the greatest lessons, and it's that very concept that keeps me thriving too.
Think of life like going down two paths, the right and the wrong. Two people come along and tell you which path to choose. One says "go to the right. It's the safe path." You could listen and follow them, but never know what would have been had you gone to the left. Could have been better, could have been worse. I'd rather trust the person who says "Go to the right. I've been down the left path, and I can assure you, you don't want to be there."
Mistakes should encourage you, not discourage you. When you fail at something, it should double your inspiration to get it right. Nothing worth achieving comes easily. It's failure and struggle that builds the legend, because lucky is the man who stumbled upon his great fortunes, but great is the man who earned them. And never let past mistakes hold you back. If you're dwelling on something you did wrong in the past, unable to forgive yourself for it, get over it now, here, today. The best part about those mistakes is that you've already made them, and even more encouraging to know, you won't have to make them again in the future. That stage in your life is over, so don't dwell on it. Take it, learn from it, and move forward. You're free from it.
The fear of mistakes is what causes ultimate failure. To fear mistakes means to fear the attempt, and without attempt, there can be no success. Never let the fear of failure keep you from trying, because only then will you lose. In fact, go headfirst with every desire to make as many mistakes as possible, to try out every possible route, knowing full well that only 20% of them will get you want you want. But know this, that mistakes can never break you. You can only begin to grow through experience. Sitting safe at home, sticking to what you know will work, will stagnant your creativity and limit your potential.
Knowing that, why don't you go out there and make you some mistakes? It builds character. ☺