I founded Gensler—an organization that today includes 5,000 employees in 46 locations—50 years ago. When we began, we had three employees and $200 in the bank. How did we manage to grow our company from a mom-and-pop shop into a leading global design firm?

The foundation for our success lies in observing key principles, which I share in Art’s Principles, my new book. One of these principles centers on leveraging unanticipated opportunities, and that’s something any entrepreneur starting a professional services firm must be able to do. Here’s an example:

When I was running late in a meeting in New York, I called my assistant to rearrange my flight schedule. She called back to say she refused to make the flight arrangements because the airline would charge $1,000 to change my ticket back to San Francisco. I appreciated her frugal nature but needed to get home. We needed another way.

Being cheap (and cautious with our firm’s money) I told her about a new airline, JetBlue, that had flights to San Francisco for only $115. She argued that they had only coach seats and that I didn’t fit very well in a coach seat. (I’m tall.) But for the difference in cost, I finally convinced her to get me a seat on JetBlue’s later flight.

Later, as I was settling into my plane seat, a man’s voice came on the PA system. He introduced himself as David Neeleman, founder and CEO of JetBlue (JBLU). He said that he would be joining the flight attendants to serve drinks, and he hoped to talk to every passenger. I thought this was fantastic and was suddenly glad to be sitting farther back in the plane because it gave me a few moments to think about how I would introduce myself.

When David Neeleman reached my seat, he asked what I did. “I’m an architect,” I said, adding, “We do airports.”

Those three little words changed everything.

He replied, “I’m trying to build a new terminal at JFK and am not happy with the architect the Port Authority suggested.” We exchanged business cards.

Two weeks later, I received a request for proposal for the terminal project at John F. Kennedy International Airport. Three weeks later, JetBlue selected Gensler as its architect. In the years since, we’ve worked on more than a dozen projects with JetBlue, ranging from full airport terminal design, to exterior signage, and even a lodge where JetBlue employees go for executive training.

Today, Gensler continues to work with JetBlue, and it all goes back to that first introduction and three simple words shared between David Neeleman and me. When he offered me the opportunity to introduce myself, I seized it—by letting him know that I design airports. Now we have designed airports for him.

Luck is not a strategy; the key is to recognize it when it comes your way. You must both welcome the serendipitous and also act on it.

If I hadn’t shared my background and experience with architecture and airports during that brief conversation with David Neelemen, I might not be telling you this success story. As a study conducted by the Harvard Business Review shows, surprisingly often, people mistakenly assume that others recognize and appreciate their experience, when this is not the case.

Getting to know people before getting down to business is one way to discover unanticipated opportunities. Let your mind expand with the possibilities, embrace them, and leverage them to increase visibility. Fear can’t be the obstacle that prevents you from jumping in and trying something new.

Curiosity is the building block upon which luck expands. The stronger your curiosity, the more unforeseen opportunities you will discover. Asking yourself how you can take advantage of the events or people you encounter will open up unanticipated avenues and reveal untapped resources.

Exploration in turn follows curiosity. This may mean venturing into uncharted territory, taking a fresh look at the familiar (such as your defined talents or areas of expertise), looking at the potential from a different perspective, and asking yourself what you can honestly bring to the table.

To be the best entrepreneur, you must trust your gut, take risks, and embrace opportunity. I have always tried to put myself out there, interact with chance encounters, and keep a constant eye on what could be. And I’ve always been astonished by not only how often unanticipated opportunities happen, but also by the amazing places they’ve taken me, and my firm.

Arthur Gensler, FAIA, is an architect and founder of Gensler, a leading global design firm. When he started his company, he knew a lot about architecture but very little about running a business. In 2015, he wrote Art’s Principles to offer today’s entrepreneurs the business insights he wishes someone had given him when he was first starting out.