How Do You Keep Your Mind Clean and Pure?

Picking up a newspaper means you’re putting darkness into your mind. People standing in line at the movies are paying money to have their minds ruined. Because once you get foolishness into your mind, you can never get it out. Even when you do teshuva (repentance), the foolishness remains in your head. Teshuva covers up the foolishness with layers of chachma (wisdom). But the foolishness is still there. — Five Minutes a Day