I learned about the book from a Twitter reference and then learned about the website. It has an underlying premise that I have encountered in a number of other books that the unconscious brain has a lot more control of your "conscious" decisions than you are conscious of.
Derek McRaney breaks it down in the book to 48 misconceptions and demonstrates the underlying reason for these misconceptions. Basically your brain uses short cuts. We are forced to make countless minute decisions every day (or every hour for that matter) and could be paralyzed without some easier (evolution tested) way to simplify matters.
Free will is an abstract concept that Derek refers to towards the end of each chapter suggesting the more you understand of what you don't understand the better your choices.
It is not my intention to cover every misconception, but a few stood out in my mind.
The human brain has a deep desire to be right all the time. Often you have to stretch to achieve this result. Amazingly facts fade and get distorted to fit the current viewpoint.
One quote in the middle from Charles Darwin, "Ignorance more frequently begets confidence than does knowledge." David, without disagreeing with Darwin would suggest knowledge might help you make better decisions.
A theme in one chapter is about learned helplessness. Studies have been done in nursing homes, prisons and homeless shelters comparing situations where little details are taken care of by staff to where the inmates are given some responsibilities. Choice makes people happier.
The human mind seeks meaning in random events. McRaney takes a dig at the idea of a soul mate. Carl Sagan, the example he uses was very happy to share this planet with his wife, but knew it was not fate.
A lot of experiments have been done on first impressions. Unfortunately they are hard to overcome. A similar theme is anchoring where your judgment can be affected by objects or ideas presented prior to a particular decision. Associations that can be made deliberate can also affect your judgment.
Procrasination is a normal phenomenon. You need to outsmart your brain with such things as prompts, positive associations, other people to remind you and do not rely on your will power.
He points out that using groups to develop new ideas is fraught with danger. The key really is to convince everyone there are not negative consequences to expressing their real thoughts. The problem is aggravated if the group contains anyone with the ability to fire the others. Another danger in groups is that many individuals loaf relying on others to speak and do the hard thinking.
One practical bit of advice is that venting can actually increase your anger. It has been proven that a better strategy is to take a deep breath. Often, as an example when someone vents their frustration on a punching bag their anger rises to a higher level.
I would recommend this book. As humans try to understand the world, they need also to understand themselves. To get a more up to date perspective on David McRaney's thinking check his website: http://youarenotsosmart.com/