There is far more opportunity than there is ability.
Success tends to go not to the person who is error-free, because he also tends to be risk-averse. Rather it goes to the person who recognizes that life is pretty much a percentage business. It isn't making mistakes that's critical; it's correcting them and getting on with the principal task.
One of these days in your travels, a guy is going to come up to you and show you a nice brand-new deck of cards on which the seal is not yet broken, and this guy is going to offer to bet you that he can make the Jack of Spades jump out of the deck and squirt cider in your ear. But, son, do not bet this man, for as sure as you are standing there, you are going to end up with an earful of cider.
Like a procession you walk together towards your god-self.You are the way and the wayfarers.And when one of you falls down he falls for those behind him, a caution against the stumbling stone.Ay, and he falls for those ahead of him, who though faster and surer of foot, yet removed not the stumbling stone.
At that moment, Harry fully understood for the first time why people said Dumbledore was the only wizard Voldemort had ever feared. The look upon Dumbledore's face as he stared down at the unconscious form of Mad-Eye moody was more terrible than Harry could have ever imagined. There was no benign smile upon Dumbledore's face, no twinkle in the eyes behind the spectacles. There was cold fury in every line of the ancient face; a sense of power radiated from Dumbledore as though he were giving off burning heat.