Three misconceptions about differentiated instruction prevent some teachers from using it: it is just another new fad that will fade away; it requires a separate lesson plan for every student; and it is not worth the effort. Examining those ideas through the perspectives of actual teaching experience and sound research proves them to be just what they are: faulty thinking. In clarifying those misconceptions, this article offers numerous examples of successful differentiation and makes the case for its prominent place in every teacher's repertoire.