It is unwise to make mistakes without being able to understand them; it is not courageous to know but not be able to change them. If you use copper as a mirror, you can straighten your clothes; if you use ancient times as a mirror, you can know the ups and downs; if you use people as a mirror, you can know gains and losses. People cannot live without criticism and self-criticism, otherwise a person cannot make progress. Self-criticism is as important to us as sunlight, air, and water. If there are any, then correct them; if not, then encourage them. In the revolutionary cause, recognizing one's shortcomings is equivalent to correcting more than half of them.

1. Self-criticism is as important to us as sunlight, air, and water. ——Stalin 2. If you know your mistakes and can correct them, there is no greater good. 3. It’s never too late to correct your mistakes once you know they’re wrong. ——Shakespeare 4. In the revolutionary cause, recognizing one's shortcomings is equivalent to correcting more than half of them. ——Lenin 5. If you don’t be prepared for others, you will fail to detect yourself. ——"Shang Shu? Yi Xun" 6. If there are any, change them, if not, add encouragement. ——Zhu Xi 7. Using copper as a mirror, you can straighten your clothes; using ancient times as a mirror, you can know the ups and downs; using people as a mirror, you can understand gains and losses. ——"Old Tang Book? Biography of Wei Zheng" 8. A person cannot trip over the same stone twice. 9. It’s not too late to make amends. 10. No one is perfect. Everyone makes mistakes. As long as they correct themselves, everything will be good. 11. Who has no fault? If you can change your past, there is no greater good. ——"Zuo Zhuan? The Second Year of Xuangong" 12. The greatest wisdom in the world lies in understanding one's own weaknesses. ——France 13. People are not afraid of making mistakes. What is terrible is doing wrong things throughout their lives.