Maurice Sendak had to illustrate many other picture books in order to gain enough credibility to do one of his own. But when the time finally came, he had a great idea. He wanted to write and illustrate a book called Where the Wild Horses Are. His editor, who was familiar with his drawings and believed he had what it took to be successful, loved the idea right away and hired him to do the book.
But there was one small problem.
After trying and trying, Sendak realized he simply couldn't draw horses. So he experimented to see just what he could draw, and he came up with, well, things. So he changed the creatures in the title from horses to "things," and a classic was born.
Kind of makes you wonder what the story would have been like if Sendak had been able to draw horses.