The author thinks they made the wrong move a few times during their career, and now they're replaying it in hindsight as if their present experience has a measure on previous performance. They are only able to write this post because they did some things badly in the past, but after a load of other steps they got to a point where they could write a post or a book and basically skip all of the hard bits they don't want to talk about.

You have to be careful to not be led into this, as if you can follow OP's self-help advice and skip the failures. You will, in fact, fail in a different way.

Is this cynical? Yes. But it's how self-help advice works.