When Bola Sokunbi landed her first job after university, she had no investment strategy up to the point of retirement. She had just been employed as a technology consultant with an annual salary of $54,000.

While going through her appointment documents during orientation, she came across the words 401(k) and employer-sponsored retirement plan which left her thinking. The retirement age of 65 years, she thought, was so far away.

During the second day of orientation, she was ready to tune out during the overview of her employer-sponsored retirement plans and their 401(k) when she heard two important words — “free money.” These two words would turn out to be a game-changer for her.

“I learned my employer was offering a free contribution match of 100% up to 6% of my own contributions. I might not have known or even cared about the 401(k) at the time, but I knew a good deal when I saw one, so I signed up and made sure I contributed just enough to get the full match,” Sokunbi told CNBC Make It.

A few months after enrolling, Sokunbi began to see how quickly the money was accumulating, and she got interested in contributing more than was required to get the match. Curious about how investing works, she committed to learning.

She started reading books and learned what mutual funds, expense ratios, diversification and asset allocation were. She even opened a non-retirement brokerage account and created watchlists for individual stocks that she liked.

While doing this, she made mistakes. “I bought stocks because they were ‘hot,’” she said. “I panicked when the market fell and sold too quickly, losing money as a result. I happily cashed out of stocks that had made returns, only to be deflated when I saw the taxes I had to pay (which I had no idea about) at the end of the year.”

She said her mistakes were costly, but they taught her how investing worked and established her comfort level with risk.

Sokunbi left her first job but during her time there, her money was invested in the limited mutual fund offerings they had. She built her contributions up to where she was not only getting the full match but also maxing out her allowable contributions.

“Once I left, four years later, I had well over $70,000 in that 401(k) from my contributions, my employer’s match, and the gains I had earned from my investments in the stock market. I couldn’t believe it! I then rolled my retirement money over into a traditional IRA and invested my money in my choice of index funds,” she told CNBC Make It.

At her new job, Sokunbi did not slow down on her investment plans. As soon as she became eligible to invest with her employer’s plan, she did that as well. This time, not only was she getting her employer’s full match, but she decided to fully max out my contributions right away.

In five years, the retirement plan Sokunbi had with her new employers grew to over $100,000.

“Since I began contributing to the plan almost right away, I didn’t give myself a chance to get used to seeing that money included as part of my paycheck, so I didn’t miss it. Instead, I was focused on my investments in my non-retirement accounts, my savings, real estate, and my side hustles,” she noted.

Sokunbi said the investment story would have been different today if she had listened to her younger self saying no to that 401(k). “It’s easy to overthink yourself into a standstill and fear the unknown. But, when you set the intent to succeed and start taking action, no matter how small at first, it’s just a matter of time before you start to reap the rewards,” she said.

Sokubi is now a certified financial planner and author of “Clever Girl Finance: Learn How Investing Works, Grow Your Money.” She is also the recipient of the 2021 Financial Education Instructor of the Year (FEIY) Award from the National Council of Financial Educators.