What advice would a 30-year-old married man give to an unmarried man? 1. Never associate with a mother-in-law's family that is dirty, messy, and poorly maintained. 2. Never speak too loudly or seek to show off. 3. Never lack savings awareness. 4. Never refuse to let your partner accompany you during medical examinations. 5. Never have poor math skills and lack logical thinking. 6. Never have no status in your father-in-law's house. 7. Never be generally educated but hot-tempered. 8. Never change jobs frequently. 9. Never act as a commander in family group activities, just talking but not taking action.