A 31-year-old self-made millionaire explains how wealth has changed his view of success

Ryan Gilliam says he always wanted to achieve significance.

"I wanted to be considered important when I walked into a room, and I thought money would accomplish that," he told Business Insider.

Guided by his ambitions, Gilliam became a self-made millionaire after selling his medical practice in his mid-20s.

However, the now 31-year-old author of "The Cost of Greatness" said once he achieved the milestone that he'd always considered a marker of success, his understanding of success began to change.

"Everyone in our circles thought I was just all that and a bag of chips - but my wife didn't agree," he said. "I wasn't home. I wasn't there emotionally. I could see the trajectory: If I continued on that path I wasn't going to spend time with my children. I wouldn't have the memories and moments that I grew up with that would be important and significant."

The father of two realized that however much money he earned, it never felt like enough, and he wasn't willing to sacrifice time with his family to earn it.

"Don't misunderstand," he cautions, "I like money and the freedom to come and go as I please, but it's not worth your family and your purpose and the memories or the laughter and joy. Money is not the greatest achievement; learning about yourself, that you are so much more and can still be happy and have joy without the money, that is the message. People my age might not agree with that, but personally, from life experience, I would rather joy and peace than extra few commas in my bank account that come with a lot of stress and anxiety."