I've found that the best teachers are the ones who have lived the lessons they teach the hard way, as opposed to gliding along a path to success, because they're the ones who appreciate the intentionality and deliberateness of sculpting their mental model. In this, Mark Manson ranks among the very best I've encountered. There are so many good nuggets of wisdom, and so very little bullshit, embedded within these pages that it's clear the hardships he's been through are true and formative.
One look at this Hacker News post, and it's clear anybody can see there really is no correlation between material success and progress, and mental / emotional / psychological health. Stressors are common and effective coping mechanisms are rare, particularly for problems that appear intractable. Mark does a great job of breaking down problems into things a skeptical conscious can believe, and weaves these bitter truths into a web of reality. In this way, the world can break down and things will still be okay.
Mark has a gift in teaching this mindset, and in speaking in vernacular that resonates with people of his and younger generations. Highly encourage people to get and read through this book to see how you can improve your personal psychological failure models.