Ray Bradbury's classic dystopian novel, Fahrenheit 451, imagines a future where firemen burn books rather than stop fires. The protagonist, Guy Montag, is one of those firemen charged with burning any and all books. In this future world, books are seen as dangerous, because they contain ideas different than those of the government and can cause dissent. Instead of reading, citizens spend most of their time watching plot-less shows on huge room-size televisions.
But there are still dissenters out there, those who keep books hidden in secret places. Even though it is Montag's job to burn the books he finds, he decides to save some and hide them himself. He is not sure himself why he does so. But he has them hidden from his wife in their house, right under her nose.
One could also argue that Montag has hidden much more than a few books from her, however. Within him, there's a growing curiosity about what the books say and why they are supposedly so bad. His intellectual curiosity is first piqued by a new neighbor and grows stronger throughout the book. But he feels disconnected from his drugged, T.V. obsessed wife, and so hides this from her as well.