Book excerpt: Concentration is a choice. It excludes all except its object of concentration; it is a narrowing. If you are walking on the street, you will have to narrow your consciousness in order to walk. You cannot ordinarily be aware of all that is happening because if you are aware of everything that is happening you will become unfocused. So concentration is a need. Concentration of the mind is a need in order to live–to survive and exist. That is why every culture, in its own way, tries to narrow the mind of the child.