It may be that the most important element of effective communication is repetition, even while it is the most unappreciated. We tend to arrogantly claim that we only need to hear things once. When a parent repeats an instruction, children roll their eyes. When a boss repeats a familiar command, employees complain that it is superfluous. When a teacher reviews material already taught, students complain they already know the material. We tend to believe we can receive information or commands and never again need a reminder or renewed encouragement.