1. Dr. Seuss' real name is Theodore Seuss Geisel.
2. "Oh, the Places You'll Go" sells about 200,000 copies a year, mostly because of its popularity as a high school and college graduation gifts.
3. "The Cat in the Hat" uses 225 words and "Green Eggs and Ham" uses exactly 50.
In case you were wondering, those 50 words are: a, am, and, anywhere, are, be, boat, box, car, could, dark, do, eat, eggs, fox, goat, good, green, ham, here, house, I, if, in, let, like, may, me, mouse, not, on, or, rain, Sam, say, see, so, thank, that, the, them, there, they, train, tree, try, will, with, would, you.
4. Dr. Seuss was an outspoken liberal Democrat. It is widely believed that "The Lorax" is his interpretation on environmental issues and an expression of his belief that humans are destroying nature.
5. "If I Ran the Zoo," written in 1950, is the first recorded instance of the usage of the word, "nerd."
6. March 2nd, Dr. Seuss' birthday, has been adopted as the National Read Across America Day, an initiative started by the National Education Association
7. Though he devoted most of his life to writing children's books, Dr. Seuss never had children of his own.
8. The German surname, "Seuss," is actually pronounced "SOYSS," rhyming with "voice." Geisel switched to the anglicized pronunciation, "SOOS," because it "evoked a figure advantageous for an author of children’s books to be associated with" - Mother Goose - and because most people used this pronunciation.
9. Over the course of his long career Geisel wrote over 60 books. Though most were published under his well-known pseudonym, Dr. Seuss, he also authored over a dozen books as Theo LeSieg and one as Rosetta Stone.
10. Dr. Seuss' first book that he wrote and illustrated, "And to Think That I Saw It On Mulberry Street," was rejected 27 times before it was published by Vanguard Press in 1937.