I have observed that all human beings, no matter how stunning their personalities can be, deep down share a common fear, though the degree of this fear varies: the fear of being lonely in an over-crowded world. Good friends will teach you to overcome this fear. They will bear the worst of you, they will bring out the best in you, and in appreciating the person that you are instead of the image which you want to project of yourself, they will teach you to value your intrinsic self. Theoretically, that could imply stuck self-development. But practically speaking, it is in truly accepting yourself that you can aim to become better. It is in knowing your faults that you can subside, if not completely eliminate them. And friends help you, to become better.