Everyone knows John Legend is exceptional when it comes to singing and songwriting. But did you know he can also put together a mean PowerPoint presentation?

Before musician and actor Legend, 39, was the first African American male EGOT (that's Emmy-Grammy-Oscar-and-Tony-winner), his post-college years were defined by a relatable grind in corporate America — an experience that ultimately taught him an important life lesson.

"I was like, I don't want to do this forever," Legend tells CNBC Make It. "Now, I'm doing what I really wanted to do."

Legend inked his first record deal at 25, but before that, after he graduated from the University of Pennsylvania in 1999 (magna cum laude), he was living with roommates in a walk-up on 7th Street and 2nd Avenue in New York City's East Village, paying "probably like $1,500" a month, he says.

"It was me and two of my friends from college we all had, like, corporate jobs," Legend tells CNBC Make It. "I was a management consultant, one was working at an investment bank, another was working at another management consultancy. We were doing what you would expect kids that graduated from Penn to do.

"It was fine...I did meet some great people, I learned a lot, and I think it was a powerful experience to learn more about how business works, how to work in groups, make a PowerPoint presentation," Legend says, smiling. "It comes in very handy."

But Legend, knew there was more to life than that. He had always wanted to be a performer and was determined to stick with it even though his music career didn't take off right away.

"You learn that sometimes you have to do things you don't absolutely love," Legend says. "But always have something in mind for your future that you're working towards."

Indeed, Legend continued to pursue his dream: At night after work, he would write songs and perform small, local gigs. He was rejected from every major label before getting his first, major recording contract in 2004.

It was an experience that shaped him.

"I think that if you feel like you have a goal and you have something out in the distance, even if it's not immediate, that you can work toward, it's really powerful," Legend says. "It helps motivate you, it keeps you going, it helps you wake up in the morning. I think that's a powerful thing.

"Sometimes you have to take detours," Legend adds. "But don't lose sight of that goal."

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