Nguyen wrote this book to find relief from his own chronic anxiety. Once he learned lessons that helped him find peace, he decided to share those lessons with others. He expresses gratitude that the book has been a major success and that readers are responding well to it and sharing it with their friends and family. 

The revised and expanded edition is based on conversations he has had with readers to clarify and build on what he originally published. In particular, he adds more detail on how to apply the book’s concepts to everyday life, including a “step-by-step methodology to help them let go of negative thinking in the simplest way possible” (11). He hopes the teachings contained in the book help the reader as much as they have helped him.

Most people are very familiar with feelings of acute self-doubt, Nguyen says, sometimes bordering on self-loathing. Low expectations of one’s abilities result in settling for the familiar, even if it’s unpleasant, rather than taking risks that could end in disappointment. People stay in jobs they hate because they don’t think they can get a better one, constantly doubt whether their friends actually like them, and are envious of everyone who seems to have it all figured out.