Don't Believe Everything You Think is a book with its heart in the right place, but its mind is elsewhere. In roughly 100 pages, Nguyen spells out a simple thesis: Our thinking is the root of our suffering. To avoid suffering, don't think. The problem is not that this thesis is simple; it's that it is simplistic. The author never really develops a cogent argument in its favor, nor does he fully equip the reader with the tools to put his suggestions into practice.
To be fair, the author is not completely off the mark. The idea that the rambling of our inner voices might be the source of our emotional troubles goes back at least thousands of years, appearing in one form or another in a wide variety of philosophies, from Buddhism to Taoism, Transcendentalism to the New Age. Even Shakespeare's melancholy Dane recognizes it in Act II, Scene 2, of Hamlet. The author acknowledges this long history chiefly in the form of chapter-starting epigraphs. The main text of these chapters, however, is big on promises ("This book was written to help you find everything you've been searching for and the answers to all the questions you've had your entire life.") but light on evidence (a few thought experiments, which is a bit ironic).
The main idea itself has more than a little truth to it. Many if not all of us have had the experience of disappearing down a mental rabbit hole, imagining arguments that never occurred, insults that were never thrown at us, catastrophes that never happened, and every other brand of mental noise that might come up. To the author's credit, he distinguishes between unbidden thoughts and indulging them by thinking. This is very much in line with the Buddhist practice of mindfulness: The thoughts will come on their own, but we need to be mindful of our taking the bait and ruminating on them.
There is some scientific support for this idea. Killingsworth and Gilbert [1] polled thousands of subjects at random points during the day to explore their activities and moods, finding that people whose minds were wandering had significantly lower moods than people who were focused on a task. Of course, like just about every published piece of psychological research, other work disagrees with this conclusion, showing instead positive effects of mind wandering [2]. The current scientific view is equivocal [3]: Sometimes it's good, and sometimes it's bad.
I am reluctant to criticize an obviously well-meaning, self-published author for deficits in the writing, but this is a short book that still feels padded and poorly edited. Beyond the distracting typos, the entire message the author has could have been contained within several pages, and nothing is added by stretching it out to book length. The biggest disappointment, though, is that there is a rich vein of material on this topic, both scientific and philosophical, that could have easily filled a book several times this one's length while maintaining essentially the same core message. Instead, the author delves into woo territory by claiming that our spontaneous thoughts are "divine downloads from the Universe," messages from God or the Great Beyond, as opposed to the product of the deeply mysterious but no less fascinating activity of the human brain. This pseudoreligious, New-Agey turn wound up being even more distracting to me than the editing.
The potential reader can get nearly everything this book has to offer from its final pages (99–119 in my edition). While the book itself is a bit of a disappointment, one would be rash to completely discard its cautions against letting our minds run away with us all the time. But the solution to a hard problem—whether it's resolving a dilemma, tackling a scientific mystery, or writing a book–requires not just waiting for inspiration from beyond but actual sustained thought. The question then becomes one of when to turn the crank and when to let go, and the take-home point may be to let go far more often than we want to.
[1] Killingsworth, M. A., & Gilbert, D. T. (2010). A wandering mind is an unhappy mind. Science, 330(6006), 932-932.
[2] Franklin, M. S., Mrazek, M. D., Anderson, C. L., Smallwood, J., Kingstone, A., & Schooler, J. W. (2013). The silver lining of a mind in the clouds: Interesting musings are associated with positive mood while mind-wandering. Frontiers in psychology, 4, 583.
[3] Mooneyham, B. W., & Schooler, J. W. (2013). The costs and benefits of mind-wandering: a review. Canadian Journal of Experimental Psychology/Revue canadienne de psychologie expérimentale, 67(1), 11.