For children’s author Eric Carle, immortality started with a hole puncher, said Bob Minzesheimer in USA Today. It was the late 1960s and the veteran New York commercial artist didn’t have a story idea for his third book. But he had a stack of paper on his desk that his hole puncher was turning into Swiss cheese when inspiration struck: He would write about a bookworm named Willi who nibbles holes through the pages in the reader’s hands. Fortunately, his editor balked. She liked the holes, not the worm, and suggested a caterpillar instead. Carle’s mind flashed to the brilliant butterfly that would conclude the fable. “It became a book about hope,” he says.

The Very Hungry Caterpillar ranks today as the second best-selling picture book of all time, said Ramin Setoodeh in Newsweek. Celebrating the book’s 40th anniversary last week, Carle, 80, says that his signature work and all six-dozen since were the result of both good luck and his desire to erase memories of a bleak childhood spent in World War II Germany. Born in Syracuse, N.Y., Carle had been a happy American kindergartner before his family returned to their native land. He spent the war watching bombs destroy his neighborhood. “With my books,” he says, “I try to recapture a period I should’ve had and didn’t—more fun, more nonsense, more humor.” Four decades after his butterfly moment, that impulse, he says, is still paying dividends.