Arthur Schopenhauer on Reading and Books

It would be a good thing to buy books if one could also buy the time to read them; but one usually confuses the purchase of books with the acquisition of their contents. To desire that a man should retain everything he has ever read, is the same as wishing him to retain in his stomach all that he has ever eaten. He has been bodily nourished on what he has eaten, and mentally on what he has read, and through them become what he is. As the body assimilates what is homogeneous to it, so will a man retain what interests him; in other words, what coincides with his system of thought or suits his ends.