Sitting in his Pasadena home not far from where the multi-billion dollar Trader Joe’s grocery empire first started four decades ago, 78-year-old Joe Coulombe laughs when asked about what it was like to start his own business. “I always tell other entrepreneurs that, if you can, do what I did,” he says. “Because starting out, I was able to make a lot of my business mistakes with someone else’s money.”

In 1954, fresh out of Stanford Business School, Coulombe was hired by the big drug store chain, Rexall. Intrigued by the 7-Eleven convenience store that had recently debuted in Texas, Rexall decided to test the same strategy in southern California, tapping Coulombe to head this new venture in 1958. Calling the new idea “Pronto Market,” Rexall allowed Coulombe almost unprecedented control of what grew to be a chain of six small grocery stores within just a few years. “I was the president of each store and each one was a separate corporation,” Coulombe explains, “and because I had to put in $1500 of my own money for each store, from the beginning I ran it as if it were my own business.”

Almost immediately, Coulombe began testing new ideas. Some, like being the first grocery chain in the nation to also sell health and beauty aids—not to mention his commitment to paying full-time employees livable wages—worked amazingly well; others, such as adding an in-store photo processing service, didn’t (but were still ahead of their time). “You have to be able to differentiate, even if you’re in what appears to be a commodity business,” Coulombe explains. “It’s important to keep trying new things, even if they turn out badly. I always say a mistake is just another name for R&D.”

By 1966, 18 Pronto Markets had opened, but Rexall had nonetheless lost its appetite for the venture. This left Coulombe with a fateful decision to make: stay with Rexall or buy out the stores. Sensing a major demographic shift toward more educated, well-traveled consumers, Coulombe resolved to strike out on his own, figuring he could refocus his stores to tap into this burgeoning market for more exotic foods and wines (hence the Trader Joe’s name and South Seas theme). He cobbled together enough money to finance the buyout by selling his house and getting loans from his father and grandmother as well as from his local Bank of America branch.

He continued to innovate, adding one of Trader Joe’s signature selling points—a large liquor section—early on. Throughout the 1970s, he adopted or borrowed other unconventional ideas to stay competitive, like accepting credit cards, catering to the growing health food market, and selling private label stock to keep costs down.

In 1979, Coulombe sold Trader Joe’s to a large private supermarket chain from Germany. He stayed on for another decade as CEO, retiring any formal role with the company in 1989 to pursue his other passions for wine and art. Still, his affinity for the business world remains to this day—he has since served on the boards of directors of several other companies and is currently a director for the Los Angeles-based startup True Religion Jeans. And perhaps not surprisingly, he says he now sees a strong connection between his old and new passions. “Business is a kind of art form,” Coulombe explains, “sometimes you have to do the unexpected in order to truly succeed.”