No wandering minds allowed.
Books can also provoke emotions. And emotions sometimes are even more troublesome than ideas. Emotions have led people to do all sorts of things they later regret-like, oh, throwing a book at someone else.
...books were better than travel.
Better to cry wolf over and over than never to cry wolf at all.
Some secrets are meant to be known- but once known you can never forget them.
You know, people always warn children about taking candy from strange adults. But they never warn us adults about taking candy from strange children.