Let's look at another example of how constraints can aid in creativity. Let's say you are an architect and I approach you and say "Design a house for me." Where would you start? Would you design a split-level ranch, a modern, sleek master piece, or a Victorian revival style home? Would it have one story or two? How many bathrooms? How many bathrooms? These questions can go on and on.
Now, suppose I came to you and said that I want a 5 bedroom, 4 bath, with a large study, a bonus room, and a large porch. Working with these constraints you can begin to design a house.
What does this all mean to you? Well, in short, don't see constraints as limits. See them as a means of freeing you up to focus on what is important to your project. While constraints eliminate a large selection of options that are initially available, doing so allows you to focus on what you can actually work with. It is within these constraints that your brain is free to create and be innovative.
So, go out and embrace those constraints that you once saw as limits and use them to become more creative that you thought was possible before.