During senior year of high school, three of my good friends and I were granted an extraordinary amount of freedom. We formed a rocket team to compete in a national competition. It was a great excuse to play with wood, razors, glue, and paint.

And explosives!

Qualifying for the competition required us to be off campus often to launch rockets and analyze their flights. Which required driving there, often in our own vehicles.

Though there was definitely a rule against driving our cars off campus during school time, we were the exception to the rule.

This freedom was not free, however. It was only possible thanks to two very good reasons. Did you know freedom always hangs around its two friends?

The first is discipline.

The four of us did our homework on time. We were in the advanced classes. We worked very hard to compete with each other on every quiz and test. We were studying physics and calculus and we applied our rocketry design to our homework and vice versa.

For the most part, we followed the rules and didn’t make trouble.

The second is responsibility.

We were trusted to do what we were told, even when no teachers were around. Each time we were granted a little freedom, we proved we could manage ourselves well and not abuse the power. Though we were mischievous for sure, we didn’t ever get in much trouble.

It took us years to earn a reputation for responsibility.

During senior year, these two combined to earn us freedom — glorious freedom!

Freedom to drive off campus and play games in class and many other liberties forbidden to students. Of course, this all depended on our willingness to respect the teachers’ rules, get our work done, and be a good example to the younger students.

And you know what? It felt so good to be trusted, there was no way we would abuse our freedom!

What a great life lesson.

It’s difficult to earn freedom. It takes tons of discipline and years of responsibility. Those who don’t have it resent those who do. They whine about not having it.

But those who have earned freedom have found a very good thing.

It seems those who are growing the fastest — those who are intentional and proactive with their lives — all have something in common.

They start by changing a single habit until they have mastered it. This clears the way for some powerful momentum to take over.

There is an incredible phenomenon which happens when you master a keystone habit.

It may not matter which habit, either!

For us it was money. We were exposed to Dave Ramsey and latched onto the wisdom of what he teaches about getting out of debt and living on less than you make. We read many books on the topic. We discussed it with friends and coworkers, collecting the best of everyone’s experience and insight — and discarding the rest!

It all started to make sense. We put into action what we learned by piling money onto our loans like buckets of water on a fire. We punched debt in the face! We are now debt-free and will never go back.

This was incredibly empowering, and had wonderful byproducts. Though the original exercise was purely financial, but it bled into other areas.

Insert momentum here.

We figured out wills and life insurance. We got rid of a bunch of stuff and simplified our lifestyle drastically. We sold one of our beaters and bought a nicer used car.

We even started taking more walks.

And it can all be traced to proactively mastering a keystone habit regarding money.

Growth begets growth.

For a friend, it was fitness. He now works out several times every week. The boost to his confidence and energy have been huge and undeniable.

The tremendous encouragement he found through fitness fueled him to take on new challenges.

This is the power of mastering a keystone habit.

What is your keystone habit?

Here are some ideas: Lose weight. Get a better job. Attend church regularly. Get serious help with a bad habit. Live on your own. Grow deeper relationships with friends. Smile while you talk. Delegate the tasks you hate doing. Get up early and read every morning. Throw away your television.

Any one of these may be just what you need — a keystone habit for you to work on.

Put all of your energy into following through.

And let the progress you make build momentum to carry you through the next milestone. And the next.

Growth begets growth.