That resonates deeply with me. Until my early 20s, I was terrible at absorbing any form of wisdom from anyone. I just went ahead forward into whatever interested me, with no regard for what anyone would have to say about it. I was fortunate enough to be born with a brain that worked fairly well and allowed me to get away with this behavior for the longest time.
It is for this reason that I consider my time in grad school as mostly a failure - I joined at 19 as a PhD student and left 2 years later with a Master's degree, leaving the PhD for startups, and in those 2 years I didn't achieve anything that I'd consider interesting work (completely by my own fault). Even worse, my immaturity resulted in me making very little of the absolutely brilliant advisor I had (the perfect combo: a researcher whose early work pioneered a new field and gave him enormous peer recognition, but who was still early enough in his career that he had plenty of time to devote to his students), who had high hopes for me that ended up completely unfulfilled.
It was only after a few years of working in the real world with some very smart (and some very dumb) people, getting yelled at, seeing friends get fired (I never got fired myself although I came close a few times), and a few other similar experiences that I realized that indeed my life would be much improved if I stopped and recognized that some people do have words of wisdom that hold value for me. Psychedelics and traveling the world+meeting people who had it way worse than me yet achieved way more with what they had also contributed significantly to my maturing - the rewards of it being that I now am starting to enjoy an amount of success, clarity, and reward in my work that would have been unconceivable 6 years ago (although it still feels like most of the road is ahead, as it should).
For those reasons, it feels like advice such as the one given by PG is lost: the people who need it most won't really get the importance of what he means, and the people who will get it can do so because they've already internalized it.
All that being said, I look forward to 5 years from now, when I will say things about my mid-20s similar to what I just said about my early 20s :)