How can you write about start-ups without ever having lived through a downturn? Sure, you can read about it, but the proper level of skepticism bordering on cynicism is impossible if all you've ever seen is the fat years.
Some knowledge you can only gain through experience, no matter how smart you think you are.
If you want, I'll get back on this thread in 15 years and tell you if you were right or not regarding additional accumulation of "deep knowledge" (whatever that vaguely-formed concept should represent).
>> "Are you 18? I would be surprised if you weren't."
At least to me, this comes across as sort of an arrogant comment that I really wouldn't expect on Hacker News. This whole "wisdom with age" is a lot of unfalsifiable nonsense the way I see it. Any sort of experiment I could propose would be shot down with "Oh, don't worry about it. There's just something magic about getting older, and well, you really can't say anything to challenge that.
On the other hand, novel writing is by and large a middle age and older persons' game. There are a handful of great novels from people in their twenties, but most of those authors go on to write even greater works later in life.
There are advantages and disadvantages to youth. Trying to pretend that everyone is equal and it is all a matter of how hard you try is one of the great fallacies of our era.