As one who has always been fascinated by psychology, yet not formally educated in it (beyond a few college courses) and not inclined to read dry textbooks on the subject, this book is a treat. It blends the latest research in individual and social psychology with funny anecdotes and insights into why we behave the way we do. Don't be put off by the title if it seems a bit frivolous: this is a serious, thought-provoking book (though quite humorous and entertaining, as well).
This is more or less a continuation of the author's previous book, "You Are Not So Smart", but you need not feel compelled to read the former: you don't really need to know the themes and ideas of the first book to read this one. In essence, the book shows us how knowledge and understanding of our self-delusions can be used to help us become, well, 'less dumb'. Using recent discoveries and research into behavior to help us see that we are not the objective observers of our lives we believe ourselves to be, but, rather, delusional lemmings stuck on autopilot, the author gives us 17 examples of how we fool ourselves in life.
Each example is brilliantly written and fascinating, incorporating science, funny anecdotes and trivia. But don't get the idea that this is just a whimsical 'pop psychology' book; this is a serious study of our irrational unconscious selves, yet presented in a highly entertaining way (much like how Richard Feynman could make quantum physics accessible and understandable to the average person, as Carl Sagan did with cosmology - complicated science explained in an engaging manner).
The author's central theme is that scientific method has saved - and continues to save - mankind from it's delusional dumbness. While you may deny that had you lived a few centuries ago you would have believed geese grew on trees, don't be so sure. In the example of 'Popular Belief', we learn that even today, myths and popular delusions abound: people in Korea - including highly-educated people - "know" that electric fans cause death, invisibly: If you leave a fan on when you leave the house, all of your pets will be dead when you return. But, not to worry, science will eventually save the Koreans from this delusion:
"When you believe in something, you rarely seek out evidence to the contrary to see how it matches up with your assumptions. That's the source of urban legends, folklore, superstitions, and all the rest. Skepticism is not your strong suit. In the background, while you crochet and golf and browse cat videos, people using science are fighting against your stupidity."
You will definitely be enlightened as to the nature of your own existence and the society you inhabit; it's that good of a book. Highly recommended.