One Fish, Two Fish, Red Fish, Blue Fish. How The Grinch Stole Christmas. The Cat in the Hat. Green Eggs and Ham. Today marks the birthday of Theodor Seuss Geisel, more fondly known in households across the world under his pen name, Dr. Seuss.

Dr. Seuss was actually born right here in Massachusetts in Springfield, where a National memorial sculpture garden now lives with five bronze sculptures representing some of his most beloved books and characters. Before passing away in 1991 he published 44 children’s books, each complete with poetic rhymes, fun illustrations, imaginative characters and – of course – a moral.

We grew up with Dr. Seuss, taking in and reciting his short stories and catchy verses. And while we may not have realized it, he taught many entrepreneurial lessons along the way. In fact, the first documented use of the word “nerd” is attributed to Dr. Seuss in his book If I Ran the Zoo (see below for illustration).

As we looked at some of his most recited lines and top quotes, we were struck by just how many parlayed into the life of an entrepreneur. Here are some of our favorites, and we invite you to include your most beloved Dr. Seuss quotes and entrepreneurial lessons in the comments, too!

“Be who you are and say what you feel, because those who mind don’t matter, and those who matter don’t mind.”

One of the best things about being an entrepreneur is you can be yourself. In fact, you’re forced to be yourself because, really, how much time do you have to try do anything other than that? But more applicable in this quote is the fact that while you build your startup, you will constantly have people telling you what they think about your idea/business/strategy/approach. Here’s the thing: if you are a savvy entrepreneur and on top of the customers you’re building for, you likely know your businesses and industry better than the nay-sayers — and yes, sometimes that includes VCs (just ask Larry Chang).

“The more that you read, the more things you will know. The more that you learn, the more places you’ll go.”

As an entrepreneur, you learn as much as you do. From the book I Can Read with My Eyes Shut, this quote speaks wonders to the entrepreneurial ecosystem — both online, and off — that entrepreneurs can tap into as resources. Thanks to the internet, you now don’t need to actually meet DropBox’s founder in person to learn how they acquired their initial set of customers. Instead, you can read about it on Slideshare presentations and blogs, along with many other examples, learning from past success and failures and apply them to your own startup.

“You can get help from teachers, but you are going to have to learn a lot by yourself, sitting alone in a room.”

As much as you can read and learn online, as many founders stories you can take in, and as many mentoring sessions you can land — most beneficial to the success of your startup is doing. You will learn wonders by actually iterating your product, and honing what works and doesn’t work with your actual customers.

“You have brains in your head. You have feet in your shoes. You can steer yourself, any direction you choose.”

Also from I Can Read with My Eyes Shut, this speaks to one of the lessons I learned first when diving into entrepreneurial life. At the end of the day, there is no safety net around you as an entrepreneur. There is no one else who is going to ‘figure it out.’ There is no one else who is going to execute your idea. There is only you, so be empowered!

“So the writer who breeds more words than he needs, is making a chore for the reader who reads.”

Replace word with features and you have one of the cardinal lessons of initial product and website design: make it simple! The more choices you offer to your customer is not necessarily a good thing. It can confuse. Streamline your idea and focus on the core points, in Lean Startup speak this is focusing on building the minimal viable product.

“Being crazy isn’t enough.”

Entrepeneurs are crazy. Let’s face it: at the most basic level, we work for little and for long hours. We think beyond what exists to what’s possible, and what’s not possible that we can make possible. In other words we think big. But crazy and big ideas won’t necessarily make you a successful entrepreneur: execution and devotion is key.

“If things start happening, don’t worry, don’t stew, just go right along and you’ll start happening too.”

As an entrepreneur, you probably have the big picture and ideal scenario for the opportunity you’re cornering all laid out. Here’s the thing: it’s probably never going to go just that way, and there are going to be hiccups along the way. As an entrepreneur you learn to be agile and dynamic, keeping in mind that you can’t always predict the bumps in the road, always knowing that execution will keep you carrying on.

“How did it get so late so soon?”

We couldn’t resist including this line from The Grinch. Every single day as an entrepreneur, there is never enough time in the day. Ever. That is a fact! There will always be too many things to do, so learn to to give up a bit of your perfectionism and prioritize by spending your energy in places that will have the biggest impact.

Thank Dr. Seuss for inventing the word “Nerd”!