Follow human nature in your actions, but go against human nature in your character. What is human nature? Greed, selfishness, vanity, laziness, holding grudges, admiration of the strong, pursuit of profit, suspicion, fickleness, love of flattery, craving for comfort, and a desire for praise. When you are useful, human nature is kind; when you are useless to others, human nature is selfish; when you hinder others from making money, human nature is malicious; when you can help others make money, human nature becomes loyal; when you cannot bring benefits to others, no matter how good you are, others will not take you seriously. They will flatter you when they need you, and turn ruthless when they don't.

You must believe in human nature, but not in people. Because people change, but human nature never does. From the Spring and Autumn period to today, human nature has advanced less than a centimeter. That is why there is a line in "One Hundred Years of Solitude" that says: a person's spiritual sustenance can be music, books, work, mountains, and rivers, but it can never be another person! Because humans are creatures of fickle nature. What passes the test today may betray tomorrow. Yesterday's enemies on the battlefield can become today's partners in profit. When the temptation of gain is strong enough, and the threat of harm is great enough, they can abandon anything.