A man who spent 5 years studying millionaires found one of their most important wealth-building habits starts first thing in the morning

Rich people do things differently than the average person - they find comfort in uncertainty, they pursue their passions, and they dedicate at least 15 minutes a day to just thinking.

They also wake up really early.

Take Richard Branson, self-made billionaire and founder of the Virgin Group, who wakes up at 5:45 a.m. to exercise before starting his work day. Or Square CEO Jack Dorsey, who wakes up at 5:30 a.m. to meditate and go for a six-mile jog.

Branson and Dorsey aren't the only successful people who wake up before the sun.

In his five-year study of 177 self-made millionaires, author Thomas C. Corley found that nearly 50% of them woke up at least three hours before their workday actually began.

It's a strategy to deal with inevitable daily disruptions - such as a meeting that went too long, egregious traffic, or having to pick up your sick kid from school - and still have time to accomplish everything you set out to do that day.

"Life has a way of throwing wrenches into our day," Corley explains in his book, "Change Your Habits, Change Your Life." "How many of us raise our hands in frustration at the end of a work day because the three or four things we wanted to get done were somehow replaced by unanticipated disruptions?"

These disruptions wear on us and "eventually form the belief that we have no control over our life," he writes. "This belief causes us to feel helpless."

Luckily, the solution is simple: Wake up earlier.

"Getting up at five in the morning to tackle the top three things you want to accomplish in your day allows you to regain control of your life," Corley explains. "It gives you a sense of confidence that you, indeed, direct your life. It gives you a feeling of power over your life. It put the reins of 'your' life back into 'your' hands"

If you're ready to join the 5:00 a.m. club, Corley recommends finding someone else who will join with you - an accountability partner. Next, read up on strategies to become a morning person.

Most importantly, Corley writes: "Start tomorrow."