Rule 1: Never lose money. Rule 2: Never forget Rule 1. This classic "nonsense" from Uncle Buffett actually reveals the way of life. You've heard examples like doubling your investment this year, halving it next year, or earning zero in two years, which are not very intuitive. Let's look at a table: suppose you are an excellent investor. In each 5-year bull and bear cycle, you can earn 20% returns in the first 4 years, but in the 5th year, there is a -20% drawdown. Trust me, achieving this is already very impressive.