Today on our Future Reality Lab blog I gave an example of how adding constraints to a problem can make the problem easier to solve. I suspect the principle generalizes.
Sometimes, when you have a task before you, the hardest part is simply knowing where to begin. In such cases, taking the first step can be very challenging.
By reducing the set of possibilities, constraints can help you to take that first step. The way I like to describe this is by inverting an old Zen koan:
A journey of a single step begins with a thousand miles.