You might assume that only certain wealthy folks attain financial independence. But you don't have to be rich to enjoy a life free from money worries.

The key is taking charge of your personal finances so that you're not relying on others or external factors beyond your control.

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"Financial independence means different things to different people," said Mary Ware, a Charlotte, N.C.-based certified financial planner. "It depends on your stage of life."

Young adults can establish financial independence by living on their own without help from their parents. Spouses gain financial independence by not relying on their partner's income and learning to save prudently and invest wisely.

"If you're older, it's having enough money to cover every 'what if' as it relates to long-term care," Ware said. "You understand how much [money] is coming in and coming out, how stable it is and what can change."

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Regardless of age, the most financially independent people engage in worst-case thinking. They plan for calamity and how they'd bounce back.

"Financial independence is controlling your own future," said Greg Welborn, an adviser in Pasadena, Calif. "It's knowing if you lost your income, how you'd recover."

Say you earn $200,000 a year. Instead of assuming you'll earn steadily more as you advance in your profession, you plan for sudden job loss, a health crisis or some other life-changing adverse event. 

"You don't count on that $200,000 forever," Welborn said. "If you got another job at $150,000, you'd still be financially independent if you'd be able to adjust your budget."

Some people delude themselves into thinking they're financially independent when they're not. Welborn recalls a client who felt financially independent after loading up on a highflying stock. As the stock kept soaring, the client dreamed of an early retirement.

But Welborn disabused him of that notion. "You're not financially independent," he told the client. "You're too dependent on that stock. You can't retire on that huge concentration in one stock."

Both Welborn and Ware caution clients not to equate financial independence with attaining a certain level of net worth. If you say, "I've hit this number so I'm all set," think again.