Real knowledge is to know the extent of one’s own ignorance. ~ Confucius
“If you’re not angry, you’re either a stone, or you’re too sick to be angry. You should be angry. You must not be bitter. Bitterness is like cancer. It eats upon the host. It doesn’t do anything to the object of displeasure. So use that anger, yes. You write it. You paint it. You dance it. You march it. You vote it. You do everything about it. You talk it. Never stop talking it.” Maya Angelou
A disposition to regard anything short of perfection as unacceptable; especially : the setting of unrealistically demanding goals accompanied by a disposition to regard failure to achieve them as unacceptable and a sign of personal worthlessness.
Merriam Webster Online Dictionary
The unfed mind devours itself. Gore Vidal
Remove self-love from love, and not much would be left. Chamfort