“Sometimes I’ve believed as many as six impossible things before breakfast,” the White Queen famously declares in Lewis Carroll’s Through the Looking Glass. Nearly all of the best children’s books are full of impossible things: talking bears and spiders, magical wardrobes and toll booths, or crayons that turn imagination into reality.

Harold and the Purple Crayon, Crockett Johnson’s 1955 classic, is one such story. During a recent event at the Library of Congress, actress Zooey Deschanel described it as the elusive book that holds the attention of both children and parents.