Constraints are critical for everything you do. They reduce the need for superfluous decisions early on. Forcing these early constraints takes some weight off your shoulders. They allow you to start taking action immediately.
They also foster creativity because they invite new challenges to work through. Instead of unlimited optionality while designing your website, only use three colors. Now you have to play around and figure out how to make it look nice.
This can apply to learning new skills too. Instead of trying to master all of statistics, start with a specific topic, like probability or distributions. Instead of reading every book on distributions, pick 1-2 courses or books. And instead of taking forever to study it, finish it within a week.
Constraints keep you focused. If you try to do everything, you’ll accomplish nothing. There is too much to learn and do, so without constraints, you'll fall into a pit of overwhelm.