Theodor Geisel, better known by his pen name, Dr. Seuss, wrote more than 40 beloved children’s books. With such classics as The Cat in the Hat, Green Eggs and Ham, and How the Grinch Stole Christmas, Dr. Seuss earned an enduring place in the hearts of children everywhere. That’s a pretty good accomplishment for a man who didn’t even like children. According Audrey Geisel, the author’s widow, he was slightly afraid of children. She said he was always thinking: “What might they do next? What might they ask next?” She added: “He couldn’t just sit down on the floor and play with them.”

Though he devoted most of his life to writing children’s books, Geisel had no children of his own. He said, “You have ’em; I’ll entertain ’em.” Mrs. Geisel said her husband “lived his whole life without children, and he was very happy without children.”

Children may have made Dr. Seuss uncomfortable, but they also made him quite wealthy. His estate was estimated to be worth in excess of $11 million in 2012.