I think the most suitable place for investors to read the book 'Principles' is not in managing companies. But it makes one thing clear: The sign of a person's maturity is not always doing the right thing. But every time I make a mistake, can I turn it into a system. Many people invest and only blame the market after losing money. Blame the Federal Reserve. Blame the banker. Strange news. Blame yourself for bad luck. But truly powerful people don't stay in their emotions forever. They will review: Is this loss due to a wrong direction? Or is the position too heavy? Did you chase after yourself? Still haven't figured out the stop loss and holding logic in advance? This is an important idea in the Principles: Pain itself has no value, only pain after reflection has value. If you experience a pullback and it's just uncomfortable, then it's just a loss. But if you extract a rule from it, it becomes experience. for example Don't touch assets that you don't understand. A single position cannot be too heavy. Don't use leverage to prove yourself. Think carefully about the selling conditions before buying. The hotter the market, the more you need to check your position. Review the system first after losses, don't rush to recoup. These things sound very simple. But there are few people who can truly execute it in the long run. Because most people are not lacking in reason. There is a lack of a reusable decision-making process. Investment and life are actually very similar. You set goals. Encountered a problem. Diagnose the cause. Design proposal. Execute Then continue to revise based on the results. These five steps may seem clumsy, but they are much more reliable than making decisions based on intuition. Many people lose money not because they are not smart. But every time I'm patting my head again. I heard a message today. Change direction tomorrow. The day after tomorrow, when I see someone else making money, I feel like I missed out. In the end, the account did not lose to the market, but to its own chaos. What 'Principles' really wants to say is not to make you a person without emotions. But it allows you to still have a process to rely on when emotions arise. When the market rises, one is not carried away by excitement. When the market falls, one is not controlled by fear. When you make a wrong judgment, don't bear it for the sake of face. When making money, don't mistake luck for ability. I increasingly feel that the most expensive thing in investment is not information, but the ability to review. Because information is available every day. Hotspots are changing every day. But whether you can extract rules from your mistakes determines whether you can become more stable as you continue to do so. Ordinary people make choices based on their feelings. Mature people make decisions based on principles. What really widens the gap is not a single judgment being right. But can you turn every mistake into a better system for the next time.