1. They Don’t Waste Time Feeling Sorry for Themselves
2. They Don’t Give Away Their Power
3. They Don’t Shy Away from Change
4. They Don’t Waste Energy on Things They Can’t Control
5. They Don’t Worry About Pleasing Everyone
6. They Don’t Fear Taking Calculated Risks
7. They Don’t Dwell on the Past
8. They Don’t Make the Same Mistakes Over and Over
9. They Don’t Resent Other People’s Success
10. They Don’t Give Up After the First Failure
11. They Don’t Fear Alone Time
12. They Don’t Feel the World Owes Them Anything
13. They Don’t Expect Immediate Results

Source: 13 Things Mentally Strong People Don’t Do by Amy Morin, LCSW.