At Edge.com, V.S. Ramachandran began his talk titled “Adventures in Behavioral Neurology with this description of the brain:

Let me tell you about the problem confronting us. The brain is a 1.5 kilogram mass of jelly, the consistency of tofu, you can hold it in the palm of your hand, yet it can contemplate the vastness of space and time, the meaning of infinity and the meaning of existence. It can ask questions about who am I, where do I come from, questions about love and beauty, aesthetics, and art, and all these questions arising from this lump of jelly. It is truly the greatest of mysteries. The question is how does it come about?

When you look at the structure of the brain it’s made up of neurons. Of course, everybody knows that these days. There are 100 billion of these nerve cells. Each of these cells makes about 1,000 to 10,000 contacts with other neurons. From this information people have calculated that the number of possible brain states, of permutations and combinations of brain activity, exceeds the number of elementary particles in the universe.