Six mistakes mankind keeps making century after century:

1. "Believing that personal gain is made by crushing others;

2. Worrying about things that cannot be changed or corrected;

3. Insisting that a thing is impossible because we cannot accomplish it;

4. Refusing to set aside trivial preferences;

5. Neglecting development and refinement of the mind;

6. Attempting to compel others to believe and live as we do."

Marcus Tullius Cicero