From the Commonplace Book:

When one is young, one venerates and despises without that art of nuance which constitutes life’s greatest prize, and it is only fair that one has to pay dearly for having assaulted men and things in this manner with Yes and No. Everything is arranged so that the worst of tastes, the taste for the unconditional, should be cruelly fooled and abused until a man learns to put a little art into his feelings and rather to risk trying even what is artificial: as the real artists of life do. The wrathful and reverent attitudes characteristic of youth do not seem to permit themselves any rest until they have forged men and things in such a way that these attitudes may be vented on them:—after all, youth in itself has something of forgery and deception. Later, when the young soul, tortured by all kinds of disappointments, finally turns suspiciously against itself, still hot and wild, even in its suspicion and pangs of conscience: how angry it is with itself now, how it tears itself to pieces, impatiently, how it takes revenge for its long self-delusion, just as if it had been a deliberate blindness! In this transition one punishes oneself with mistrust against one’s own feelings; one tortures one’s own enthusiasm with doubts, indeed, one experiences even a good conscience as a danger, as if it were a way of wrapping oneself in veils and the exhaustion of subtler honesty; and above all one takes sides, takes sides on principle, against "youth."— A decade later: one comprehends that all this, too—was youth!

Friedrich Nietzsche, Beyond Good And Evil § 31.