Teaching is fundamentally about communicating, and all communication begins with getting your audience's attention. You may propose to your spouse by writing “I love you” in the sand. You may speak to your son about behavior problems by moving him to the kitchen table, turning off all distractions, looking him in the eyes, and starting with “We need to talk.” Martin Luther King did not begin with “I will present eight reasons why Blacks should have the same rights as Whites,” but rather “I have a dream” because the metaphor of a dream captured and kept his audience's attention.
