Because we don't fully understand how our brains work, we do dumb things.

The title of the book might put you off and you might think that it is a demanding book to read, but it is actually quite the opposite. John did a very good job providing details of how the human brain works in a simple way by dividing the principles into 12 rules. He provides the current scientific understanding and the strongest theories on how our brains work and provides analogies and examples throughout the book which help readers easily understand the principles.

The book explained the importance of exercise (Rule # 1) and sleep (Rule #7) to enhance brain performance. Exercise increases the number of pathways for blood ( to enter the brain and the volume of blood in certain regions. Putting sleep as a priority is important because whilst we are asleep the brain is working to store what you learned that day. So really while we are sleeping and other parts of our bodies are resting, the brain is NOT! Although I have read the book twice, I still find it pretty hard to implement this every night – 24 hours a day is just not enough to do everything I want to do! Some of you can probably relate to this?!

According to John, not only is every brain wired differently (Rule #3) but there are also differences between males and females brains (Rule #11). One point that sticks to me the most is that during an emotional event,

Women activate the left hemisphere’s amygdala and remember the emotional details. Men use the right amygdala and get the gist.

What this means is that women perceive the event with more data points than men. So women are not cry-babies – we just have more information to which we can react to; and men are not cold-hearted, they just do not have as many data points as women to analyse and to respond to.

Now, have you ever wondered why certain events are still so clear in your mind even after a long period of time? For example, I still remember one day when I was 3-years old, I managed to open up the latch on the door at the top of the stairs when I was playing with my two little sisters (who were 1 and 2 years of age). This action resulted in all three of us rolling down the stairs and ending up stacked on top of each other. After all these years, I recall this occasion just as if it happened only yesterday. This is because our brains pay attention to emotionally arousing events (Rule #4). We can use this knowledge in our daily activities

Audiences check out after 10 minutes, but you can keep grabbing them back by telling narratives or creating events rich in emotion.

In this rule #4 on attention, John explained why multitasking is not possible as our brains can only pay attention to one thing at a time and it is only a myth that females can multitask. Studies show that:

a person who is interrupted takes 50% longer to accomplish a task. Not only that, he or she makes up to 50% more errors

This is good evidence of why it is extremely dangerous to use your mobile phones while driving. The book mentioned that by multitasking the risk of a crash or near-crash increases by nine times! So if you think that you can ‘manage’ driving and using a phone, you can’t. Our brains simply do not work that way.

There are seven other rules in the book that are equally interesting, so far I have only briefly described five rules. It is truly amazing how complex our brains are and how they work. The brain is the most important part of your body, pick up this book and you will be surprised at what you will learn! And ironically you will then understand how you learned it!

Note - this post was written based on the first edition of the book. In the second edition, John Medina combined the two rules on memory into one and added a new rule on music.

PS – for those who have little ones or are expecting, John also has a book called "Brain Rules for Baby" which might interest you to understand how to help your little ones’ brains develop.