Why use repetition in picture books?

Repetition plays a major, if not always obvious role, in most storytelling. It can help build patterns, which is useful in guiding readers to particular conclusions or in solving a mystery, or it can create a feeling of familiarity and comfort, which helps readers understand and buy-in to new ideas. In picture books and books for new reading learners it helps with memorization and internalization. Also, it can be really fun!