"Sometimes you have luck when you are doodling," Dr. Seuss once recalled. "I did one day when I was drawing some trees. Then I began drawing elephants. I had a window that was open, and the wind blew the elephant on top of the tree. I looked at it and said, 'What do you suppose that elephant is doing there?' The answer was: 'He is hatching an egg.' Then all I had to do was write a book about it."

The book -- Horton Hatches the Egg -- was an instant success.

"I've left that window open ever since," Seuss once said, "but it's never happened again."

[Before Vanguard Press picked it up in 1937, Seuss's To Think That I Saw It on Mulberry Street was rejected by 27 publishers. "The excuse I got for all those rejections," Seuss later recalled, "was that there was nothing on the market quite like it, so they didn't know whether it would sell."]