Earlier quoted context omitted.
Ageism is dumb, and I rally against it now as an adult as much as I did when I was 15. > "but I seriously haven't really heard someone over the age of 30 or so make snarky remarks about how so-and-so is such a hipster douchebag" Maybe that's because you surround yourself with people who have similar outlooks? That doesn't mean that all people over 30 are above high school bullshit. And it certainly doesn't mean that…
When I was under 30 or so I was ageist - I felt that most under 28 or so had a long way to go before they become human beings. Obviously, I was the exception to that rule, but even at that age I knew that my contemporaries lacked in maturity. Except... then I reached my 30s. And realized that I was not, in fact, an exception to that rule. I was perhaps worse, because I was aware of it and somehow thought I was above…
From http://www.gutenberg.org/files/4363/4363-h/4363-h.htm
Quoting at length because it's hard to extract the pith:
In our youthful years we still venerate and despise without the art of NUANCE, which is the best gain of life, and we have rightly to do hard penance for having fallen upon men and things with Yea and Nay.
Everything is so arranged that the worst of all tastes, THE TASTE FOR THE UNCONDITIONAL, is cruelly befooled and abused, until a man learns to introduce a little art into his sentiments, and prefers to try conclusions with the artificial, as do the real artists of life.
The angry and reverent spirit peculiar to youth appears to allow itself no peace, until it has suitably falsified men and things, to be able to vent its passion upon them: youth in itself even, is something falsifying and deceptive. Later on, when the young soul, tortured by continual disillusions, finally turns suspiciously against itself—still ardent and savage even in its suspicion and remorse of conscience: how it upbraids itself, how impatiently it tears itself, how it revenges itself for its long self-blinding, as though it had been a voluntary blindness!
In this transition one punishes oneself by distrust of one's sentiments; one tortures one's enthusiasm with doubt, one feels even the good conscience to be a danger, as if it were the self-concealment and lassitude of a more refined uprightness; and above all, one espouses upon principle the cause AGAINST "youth."—A decade later, and one comprehends that all this was also still—youth!