Carnegie's The Weakness of Human Nature is worth reading again and again. It describes the basic needs of people in society. For example, many famous philosophers' views on people's most fundamental needs are introduced. It is called "self-esteem", and everyone has it, so he later introduced how a person can be elegant, that is, satisfy everyone's fundamental self-esteem. Therefore, he is interested in how to communicate in life, how to work, negotiation and management at work, and so on. Everything revolves around human nature. People who understand human nature often succeed. For example, successful managers must know how to make good use of people, but they may not know how strong their skills are. But to meet a person's natural needs, someone will follow him willingly. Such as Liu Bei. Generally speaking, this is a life guide book, and I am deeply inspired by it. This book is well organized. And his trilogy "Good Life" and so on. It is worthy of repeated scrutiny, and the understanding in different periods is deeper.