If you're going to read only one book this year by a world renowned Nobel Prize Winner in Economics Sciences about the inner workings of the human mind, then you should definitely read this book (granted, I know of no other book that would fall into that category). This is a book about how we think... or more specifically, how we use two systems of thinking in everyday decisions - System 1 and System 2. System 1 is fast, intuitive, and emotional; System 2 is is slower, more deliberate and cautious. Each system has its strengths, biases, and faults. These two systems work in concert with each other to shape our choices and desires.
Ideally all of life's most important decisions should be processed slowly through system 2. Unfortunately, our System 2 is often lazy, relying on cues and biases offered up by our System 1. Rather than being consistently rational in our thinking, we are profoundly influenced by emotional (non rational) inputs from System 1 thinking. This causes individuals, corporations, and governments all sorts of problems regarding beliefs about what will make one happy, overconfidence in corporate strategies, and long term financial stability.
This was a book that I enjoyed, though the breadth and depth of the material covered seemed to go beyond my ability to fully comprehend. This seems to be Kahneman's life work collected in one book. Each chapter or point of emphasis was engaging in itself, though I had difficulty trying to see how each point connected to the whole. If you are a fan of books like Freakonomics, Outliers, Scorecasting, etc... you may like this book, especially if you want to go far deeper than those books went into human psychology and the out workings of our behavior.