As I approve of a youth that has something of the old man in him, so I am no less pleased with an old man that has something of the youth. He that follows this rule may be old in body, but can never be so in mind.Cicero
The nature of the human mind is such that unless it is stimulated by images of things acting upon it from without, all remembrance of them passes easily away.Galileo Galilei
In so far as the mind is stronger than the body, so are the ills contracted by the mind more severe than those contracted by the body.Cicero
All men whilst they are awake are in one common world: but each of them, when he is asleep, is in a world of his own.Plutarch