Hermann Hesse. Magic books (№ 449455)

But there is only one law and one and only way to be educated and grow spiritually on books - to respect what you read, to be patient in the impulse to understand, careful in judgments and be able to listen. And he who reads only in order to kill time, no matter how much and what, even the best, he reads, he will still forget everything, remaining as poor as before. But to the one who reads books as well as listens to his friends, they will open and belong. What such a person reads will not slip through his fingers and will not be lost, but will remain in him, become his property, to please and console him in the way that only friends can.