As there are misanthropists, or haters of men, there are also misologists or haters of ideas, and both spring from the same cause, which is ignorance of the world. Misanthropy arises from too great confidence of inexperience; you trust a man and think him altogether true and good and faithful, and then in a little while he turns out to be false and knavish; and then another and another, and when this has happened several times to a man, especially within the circle of his most trusted friends, as he deems them, and he has often quarreled with them, he at last hates all men, and believes that no one has any good in him at all. ...The reason is that a man, having to deal with other men, has no knowledge of them; for if he had knowledge he would have known the true state of the case, that few are the good and few the evil, and that the great majority are in the interval between them. The Trials Of Socrates

Blessed are the forgetful, for they get the better even of their blunders. Beyond Good and Evil

“Look again, and see what will naturally follow if the prisoners are released and disabused of their error. At first, when any of them is liberated and compelled suddenly to stand up and turn his neck round and walk and look towards the light, he will suffer sharp pains; the glare will distress him, and he will be unable to see the realities of which in his former state he had seen the shadows; and then conceive some one saying to him, that what he saw before was an illusion, but that now, when he is approaching nearer to being and his eye is turned towards more real existence, he has a clearer vision,—what will be his reply?” Republic

Many go out for wool, and come home shorn themselves. Don Quixote