Don't be afraid to step up and be a hero. It will boost your confidence and that, in turn, will inspire others. Maturity is not age age is not wisdom. Experience is the only true teacher, and nothing else will make you as strong or insightful. And while we're making comparisons, I'd just like to point out that tact is not hyper-sensitivity.
Diplomacy is a highly important skill that many people confuse with being politically correct.
Even a good friend is going to hurt you sometimes. Forgiveness is a virtue that cannot be paralleled, and extends not only to those who hurt you, but you must extend it to yourself as well. And as difficult as it may be, don't hold a grudge. Grudges just weigh you down with unnecessary animosity, and blind you from seeing the whole person. Sometimes the people you expect to kick you when you're down will be the ones to help you get back up.