SOURCE OF MOST UNHAPPINESS? Most of unhappiness in life is caused by the desire

SOURCE OF MOST UNHAPPINESS?

Most of unhappiness in life is caused by the desire that people behave as we wish them to, rather than to behave as they do, as they prefer to do, and as it is in their interest to do. People are rational. They act in their own interests, to the best of their ability to comprehend their interests, when offset by the risk and reward of pursuing alternative interests.

Philosophers are as guilty of this error as any other person.