In 1960, two men made a bet. The first was Bennett Cerf, the founder of the publishing firm Random House. The second was a guy called Theo Geisel. Cerf challenged Geisel to write a children’s book using only 50 different words to win 50 bucks.

The results was a little book called Green Eggs and Ham, which was published on August 12, 1960. By 2001 it had become the fourth-best selling English-language children’s book yet written. As of now the book has sold 200 million+ copies.

Theo Geisel was none other than Dr. Seuss, and this story is an example of how constraints make us creative. It shows what can be built off of a simple question like, “what if I had to use only 50 different words to write a book?”

But arbitrary constraints—that are set for the sake of setting constraints—are useless. We have to learn how to choose the appropriate constraint based on the creative goals we are pursuing.

For example, an empty canvas is an artist’s nightmare because it presents infinite possibilities. But it’s more limiting than liberating. To overcome this, we need some way to narrow our view. We need space constraints.

In the above example, instead of working with infinite words for his children’s book, Dr. Seuss had to find a way to work with only 50. This narrowing down allowed him to get creative.

When you give yourself space constraints, for example, paint with primary colours only, or write a technical essay that a 10 year old can understand, you give yourself the freedom to think inside the box. This prevents the mind from wandering.

If you are building software, the space constraint question is: “what if I could pick only one feature?” Despite that, space constraints have no control over time. If you pick a big feature, the MVP itself may take a year instead of a month. In such cases, we need to create some time constraints.

When we start a project, we set some arbitrary deadlines based on the arbitrary MVP in our mind. We can do better by asking ourselves: “what if I had only a month, how would I get this up and running?”

A time constraint forces us to get better at picking. For example, restricting yourself to get something done in a month or a week would force you think very differently than restricting yourself to get the same thing done in three months.

Brian Chesky, the founder and CEO of Airbnb, talks about an art assignment they got when he was a student at RISD. The teacher had asked the class to do a self-portrait. The students spent hours on the assignment, polishing each and every brush stroke until perfection. Once they were done, all the projects were put up in the class for display. When the students looked at each others work, they wondered how they could have done better—if only they had more time, or they had done something differently. Then they got the next assignment: to complete 200 self-portraits.

In order to do 200 self-portraits, they had to get creative and approach the problem completely differently. Deadlines define the work, not the other way around.

If you let the work define the deadline, you are promising yourself that you’ll do whatever it takes to get the project up and running, no matter what. It’s hard to find three words loaded with more inspiration, aspiration, and ambition than “whatever it takes!”

But “whatever it takes!” is a great way to do sloppy work. Edward Smith, the captain of the Titanic, gave orders to do whatever it takes to get to New York faster than expected to break the record. “Whatever it takes!” is an iceberg you should avoid.

A better approach is to ask, what will it take? It’s an invitation to add some space constraints on top of the time constraints. Now you have the room to make tradeoffs and cuts, or come up with a different approach all together.

What if you have no job a month from now? What if you have only one month worth of savings? What will it take to get a project up and running so that it generates cash the next month onwards?

Combining space constraints with time constraints gives you the right frame of mind to avoid the trivial path, and get things up and running creatively. Much like writing a children’s book with just 50 words.