Watch your thoughts; they become words. Watch your words; they become actions. Watch your actions, they become habits. Watch your habits, they become character. Watch your character; it becomes your destiny.
For the great enemy of the truth is very often not the lie – deliberate, contrived, and dishonest – but the myth – persistent, persuasive, and unrealistic.
John F. Kennedy (1917–1963)
35th president of the United States