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