This is a book about humans, a manual for us to learn how to understand humans, understand yourself and understand others. We can compare a man's life to a cup of coffee with different ingredients. For a cup of coffee to be delicious and to feel right, it has been through lots of processes to become the right coffee. The recipe to this right coffee could change the lives of millions of people. This is how to understand human nature. This is how to understand ourselves. This is how to understand the others and live with others. This is how to change.