“ Riches, pleasure, and, in a word, all external things you sometimes regard as being good and sometimes as bad; and in your relations with others, don’t you regard the same people as being good at one time and bad at another, and aren’t you sometimes well disposed towards them, and sometimes ill disposed, and don’t you praise them at one time while criticizing them at another? ”
 Epictetus, Discourses (2nd century). copy citation