It’s the 90th birthday of Eric Carle (b. 1929, #nicelonglife) and this year is the 50th birthday of Carle’s bestselling children’s book, The Very Hungry Caterpillar, which begins, “In the light of the moon a little egg lay on a leaf.” About 50 million copies of Caterpiller have sold, which means that every 30 seconds someone around the world buys the book, though not—this is important—always the same person.

Carle was born in Syracuse, New York, to German immigrants. His mother was homesick for Germany, so with shockingly bad timing, the family moved back to Stuttgart in 1935. This ended up being exactly as much fun as it sounds. Carle’s father was drafted and landed in a Russian prisoner-of-war camp, and Carle experienced firsthand the hardships of war. Carle did finish school and then studied graphic art at Akademie der bildenden Künste, graduating in 1950.

In 1952 Carle eagerly returned to the U.S., where he was soon drafted into the Korean War. (I know, right?) Before and after his time in the service, he was a graphic designer at The New York Times and then worked in advertising. He was nearly 40 when his first children’s book, Brown Bear, Brown Bear, What Do You See? (1967), a collaboration with Bill Martin, Jr., came out. Carle and Martin went on to create several more books in the same format (Polar Bear, Polar Bear, What Do You Hear?, 1991, you get the idea), but Carle also began writing/illustrating his own books all by himself. 1, 2, 3, to the Zoo came out in 1968 and was followed the next year by The Very Hungry Caterpillar.

In his first draft of Caterpillar, Carle featured a bookworm, but Carle’s editor thought “ick” so they landed on caterpillar instead. Carle came up with the idea for the book—in which the caterpillar eats his way through various foods—after playing with a hole punch. Carle has said that he’s come to believe the book is so enduring because “it is a book of hope.”

Carle has created more than 70 books using a tissue-paper collage technique and now has his own imprint at Penguin Young Readers that releases books and related products only by Carle.

Have a splendid Tuesday, perhaps enjoying “one piece of chocolate cake, one ice-cream cone, one pickle, one slice of Swiss cheese, one slice of salami, one lollipop, one piece of cherry pie, one sausage, one cupcake, and one slice of watermelon,” but no stomachache, and stay scrupulously honest to the data.