“Antisthenes … was asked on one occasion what learning was the most necessary, and he replied, "To unlearn one's bad habits."”

“When asked what learning was the most necessary, he said, "Not to unlearn what you have learned."”

“The most necessary learning is that which unlearns evil. ”

“The most useful piece of learning for the uses of life is to unlearn what is untrue.”

“The usual bad poem in somebody’s Collected Works is a learned, mannered, valued habit, a habit a little more careful than, and little emptier than, brushing one’s teeth.”

“Half of wisdom is learning what to unlearn.”

“Modern English, especially written English, is full of bad habits which spread by imitation and which can be avoided if one is willing to take the necessary trouble.”

“When the poet Paul Valery once asked Albert Einstein if he kept a notebook to record his ideas, Einstein looked at him with mild but genuine surprise. "Oh, that's not necessary," he replied. "It's so seldom I have one.”

“To be old is a glorious thing when one has not unlearned what it means to begin, this old man had perhaps first learned it thoroughly in old age.”

“One gets a bad habit of being unhappy.”