1: Stop expecting from others. Expectations only lead to disappointments.

2: Never blame anybody for your mistakes and failures.

3: Never make a promise when you are emotional.

4: Never say or do something that is going to affect anyone negatively.

5: Don't believe in things that you haven't seen by yourself.

6: Never feel ashamed to admit your mistake.

7: Never take your all friends home. Be selective. Don't trust everyone blindly.

8: Never share your personal life with everyone.

9: Never underestimate yourself. You can definitely do if you want to do.

10: Never compare your life or your people with others. The fingers on the same hand are not same so we cannot expect anyone be same.

11: Never get addicted to anything so seriously. It can be a thing or a person or a habit.

12: Never tell any secrets in front of the kid. They are catchy and can bring you an embarrassment in the public.

Source: https://humanmindreaders.quora.com/What-are-the-12-things-we-should-never-do