The first thing to know is that this book is not by Richard Dawkins (a biologist), its author's name is V.S. Ramachandran (a neurologist). Brain is the most complex of human organs. I was surprised to learn that human brain is made up of about 100 billion nerve cells, or neurons; each neuron makes from one thousand to ten thousand contact, called synapses. With all these permutations the number of possible brain states is staggeringly vast; in fact, it easily exceed the number of elementary particles in the known universe (page 17-18). I may not agree respectfully with the last part of the statement. The fact remains there is so much that remains to be discovered for both: universe and human brain. The author describes his most challenging moments as a neurologist. At times, it is easy to be distracted with the details in its 458-pages. You need a good ten to fifteen quality hours to read it with some degree of understanding. I had to read some passages again and again to remind myself of the context of discussion. Overall, this was my first experience of reading an account by a neurologist of the way they attempt to diagnose and treat mental disorders. I found them to be informative but not interesting at all times.