“ A mind needs books as a sword needs a whetstone if it is to keep its edge. That's why I read so much Jon Snow. ”
Source: A Game of Thrones
Similar Quotes
To be worthwhile, books should cause you to think. If they do that, you will find that your mind is developing. 
Your mind is not doing what you say; you do whatever your mind says. That means you are a terrible manager. 
Books are for people who wish they were somewhere else. 