It seems fairly straightforward and real wisdom is learning from others mistakes

It depends. Nothing teaches better than failure. Of course I don't need to try heroin to know it's bad, but there are many other things that are worth trying and learning from.

To tie it to HN, the vast majority of new companies fail. Wisdom would say don't waste time on a new company, yet many of us do just that.

I think this is fairly myopic. Surely you’ve experienced firsthand someone telling you something, you not “getting it” or believing them, only to be like “oh shit this person was totally right” later on? Or maybe you can like, imagine that this is a fairly normal interaction other people have?

Not necessarily. "Inner wisdom", wisdom about yourself and who you are, usually can only come from your own experiences (both mistakes/failures and successes/victories).

You can learn a lot about yourself by "blowing up" your life. (And you don't have to go to the extremes the article describes.)

It takes a while to get there… most people need to experience the pain of a few real mistakes of their own before they recognize the value of paying attention to other people’s.

The worst is seeing someone making a mistake, warning them, and then they do it anyway.

It seems real wisdom has a prerequisite: seeing other people's mistakes.

It is hard to see other people's real mistakes, both clearly and with all the context.

Also, changing the people around you can solve a surprising large number of problems.

It's not so much that people can't understand it, it's that it's wrong enough times for people to think it can apply to them. (Kinda like playing on the lottery; you won't win, but you have plenty of evidence to think you will.)