There are at least three reasons you should know Scott Cook, and one reason you probably don't. And it's that last one that might be most important.

Cook is the founder of Intuit, the company that brought you the personal and business financial tools Quicken and Quickbooks--and as Intuit's CEO for the better part of 20 years, since its launch in 1983, he built the company into a $1.7 billion enterprise. He should be more famous than he is. Not just for the fact of Intuit's success (you know other companies that grew bigger and faster), but for how Cook achieved it and what his particular entrepreneurial journey represents. Not to mention the ways his company's creations have changed how so many of us manage our financial lives.

In 1983, when he took his start-up leap, Cook was already ahead of two curves. No corporate outsider, he was a Harvard M.B.A., a former Procter & Gamble brand manager, and a onetime Bain consultant. He was, though only 32, a business pro--a forerunner in a trend that would later be labeled the "professionalization" of entrepreneurship. He also might have seemed a child of the "excellence" furor (it's the customer, stupid!), except that he began assembling Intuit even before the germinal Peters/Waterman bible was published. He wasn't riding a wave, he was pushing through the water ahead of it.

If Intuit's growth can be attributed to any one managerial practice, it would be the now tired cliche about listening to your customers--which, cliche or not, still too few companies understand or act on with any faith. Is there a smarter, simpler, cheaper, or more telling example of the practice than Intuit's "Follow Me Home" program? It called for an Intuit employee to hang around the local computer store until someone bought Quicken off the shelf (this was back when people did that sort of thing). The employee would then ask the buyer to take him home so he could see how difficult the product was to install. He would watch the process silently, noting everything from how easily the shrinkwrap came off to which lines of direction bred that confused look on the new user's face. If there were problems, the fault was Intuit's, Cook insisted, not the customer's. Every pause, every source of frustration, were evidence of something Intuit needed to fix. Cook was a radical simplifier. He knew, right from the start, that Intuit didn't need only to make Quicken better and easier than every other software program; it needed to make Quicken better and easier than the pen in your hand and the paper check-writing process that Quicken aimed to replace. And Cook knew that if he and his company could just be alert and creative and open-minded enough, then making it so was possible, because would-be customers could tell them how.

He was right. So right, in fact, that during Intuit's second decade, Cook says, customers "invented our mid-market business before we even saw the possibility." Entrepreneurs had begun using Quicken to run the finances of their companies, modifying the program to suit their needs. When Intuit finally caught on, it listened again and created Quickbooks, a business finance program that now accounts for 15% of the company's sales. (Small-business products and services as a whole account for 45%.)

And here's where it can be argued that the impact of Cook's work has been exponentially greater than merely what's reflected in the billion-dollar business he's built--that by pioneering the tools that made financial management possible for so many individuals and company builders, he and Intuit taught an entire country important things about business, and for many people made entrepreneurship itself possible, too.

For all those reasons you should already know Scott Cook better than you do, but the reason you don't is more meaningful. It's his carriage, his peculiar self-effacement, and what that leads to. It would be hard to find another brilliant man who's more unprepossessing than Cook. It's not possible that Cook is ego-less; he's too self-confident, has accomplished too much, is too secure in his convictions. But the impression he makes today isn't any different from the one he made when I first met him in 1988--a time proximate enough to one of Intuit's early near-deaths that potential failure was still a character in the room. Cook remains the slightly owlish, professorial guy he was, still looking papery and wind-carved. He speaks with the same gentle precision, thinking before talking, never the loudest voice. And in conversation he still listens unlike any leader I have ever seen. Listening, he seems to forget himself. He seems composed of pure curiosity. He's like a man who always expects that the next thing someone--anyone--tells him might be the most surprising and enlightening thing he's heard. He listens without blinking. He learns.

Recently I spoke with Cook about some of that learning. Using the occasion of Inc.'s anniversary, I asked him to consider his entrepreneurial experience (no longer Intuit's CEO, he's now chairman of the executive committee) and offer new entrepreneurs some advice. What are the secrets? If buttonholed by a CEO launching a business of his or her own and forced to be reductive, what three things would he urge that CEO to do? "The secrets?" says Cook.

"One, behave humbly. Be humble about your importance, about how many answers you know and about how much you don't know (which is always more than you think), humble about the need to engage with and learn from people around you, humble about customers, humble about learning. Please understand that I'm saying behave humbly; I don't think you can actually will yourself to be humble, but you can behave humbly. Which means saying, often, 'I was wrong.' Which you'll discover is the moment when the real insights and breakthroughs occur. And when it's hard to behave humbly because you're afraid people won't value you, just remember: People already know, they can see through you. They know what you're good at and what you're not, so don't pretend. Instead, try being true. Be human, and vulnerable the way you really are. And you'll find that by admitting you're not good at stuff you build a bridge to people. You give them room to contribute.

"Two, get a coach. Because people aren't going to tell the boss what you need to know about yourself. Bad news never travels all the way up. So get a coach who helps you, and criticizes, and makes demands, and holds you accountable. Don't you think there's a reason that even superhuman athletes, the best in the world, always have coaches? Yet how many CEOs do? I occasionally had a coach [Peter Wendell, head of Sierra Ventures] and made some of my best decisions when using him.

"And lastly," Cook says, "realize that to a scary degree a company grows to reflect its founder. Unlike with your kids, there are no unalterable genetics to blame, it's all nurture. You get to start the code. So be customer-driven. (My biggest surprise was discovering how customers will invent your business for you.) And commit to the right values--be straight, tell the truth. Especially the bad news. You'll discover that people always get over it, and even admire the effort you make trying to fix things. Short-term losses become long-term gains.

"It works," Cook says.

And then he shuts up--and, almost beckoningly, waits. Because, as in every conversation, now Scott Cook wants to know what you think.--Michael S. Hopkins

Michael S. Hopkins is an editor-at-large.