Practically everyone has happy memories of reading Dr. Seuss’s books as a kid — if nothing else, you definitely loved Green Eggs and Ham. With the author’s birthday on March 2nd, you might be wondering about his life and career and how it all started. For instance, what was Dr. Seuss’s first book? The answer to that question goes back several decades.

The first book Dr. Seuss (real name: Theodore Seuss Geisel) ever published for children under his pen name was And To Think That I Saw It On Mulberry Street. Even if you don’t remember the book, let this fact serve as some inspiration next time you’re feeling discouraged about your career goals.According to Biography, Seuss’s first book was rejected 27 times before he finally found a publisher. Vanguard Press decided to take a risk and it’s a good thing they did, or we wouldn’t have so many of the stories we’ve all read and loved while growing up. If he didn’t give up, neither should you!

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And To Think That I Saw It On Mulberry Street is about a boy named Marco telling his dad all about an imaginary parade he witnessed while they’re taking a walk — although he later admits it was all in his imagination. In 2012, Seuss expert Guy McLain told NPR that the book was likely based on Seuss’s childhood, which was spent growing up near a real-life Mulberry Street in Massachusetts.

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Dr. Seuss has been such a significant part of so many people’s childhoods, and it’s hard to believe that it all started over 80 years ago. If it’s been awhile since you’ve read his classics, it might be time for a refresher. These books can easily bring back some happy memories.