You don’t notice them because you believe they’re not there. You don’t think about them because they haven’t been created yet. But Dan Santat proves that they’re alive, thriving, and very much real in The Adventures of Beekle: the Unimaginary Friend (Little, Brown, $17). Born on an island where imaginary friends are created, Beekle waits patiently for his turn to be chosen, until he does the unimaginable: summoning the idea of a human friend to bring him courage, he journeys out into the real world. In a dark place, Beekle follows a familiar sight, and everything begins to feel a little less strange. Dan Santat’s wonderfully magical tale may make you wonder where your imaginary friend is. Ages 4-8. Allison Trotter