Not all books are created equal, more so for self help books. Bad ones, if you take their lessons to heart, will make you turn egotistical and borderline narcissistic. Good ones will give you tools to improve and guide you through steps to achieve it.

Now to answer your question, I'll say that in that light, there are people who are making mistakes towards you and people who are toxic. The people in the first category will make an effort to improve if you point-out their mistakes, the ones in the second category don't care. Because it's hard to know which is which, you should start by communicating what bothers you and then, if they keep doing it, then yes, cut them out.

Mistakes in this context is ways of treating you that you don't like to be treated in. E.g being referred to by a shorter name, that may be annoying or triggering to you or stepping too close in your personal space. In other words, something for which there is no way for the other person to know it's a mistake until you communicate it. It does not refer to actions that they know are wrong, such as taking financial advantage of you. Although for some cases, even then you could benefit by expressing your dissatisfaction, as cultural differences may come into play.