Always be learning. The market is constantly changing, and you need to keep up with it.
Everything can be taken from a man but one thing: the last of the human freedoms—to choose one's attitude in any given set of circumstances.
Efficiency is doing things right; effectiveness is doing the right things.
Man's main task in life is to give birth to himself, to become what he potentially is. The most important product of his effort is his own personality.