Today Fortune launched the Fortune 40 Under 40 Insider Network, one of several online communities where the biggest names in business answer timely career and leadership questions. This week, we ask: What’s the biggest risk you’ve ever taken? Our first answer comes from Airbnb CEO Brian Chesky.

When I graduated from the Rhode Island School of Design, I got a job at a small industrial design firm in LA. I loved it at first – I had a job that paid well, and some of my designs even ended up on store shelves.

But I felt unfulfilled designing products that would eventually end up in landfills, and wanted to build something that would last. I worked with a few entrepreneurs in LA, and it struck me that even though I was the designer, they were the ones that were creating something meaningful. I asked myself, ‘what’s the difference between them and me? Why can’t I do the same thing?’ That’s when I realized — they had taken a risk, and I hadn’t.

Then one day, I got a call from my college friend, Joe Gebbia. He had been telling me that I should move to San Francisco ever since we graduated, but this call triggered something for me, and I finally decided to take the risk. Everyone has one or two moments in their life when they make a decision and it changes their life forever. Almost every decision in my life I’ve now made is a chain reaction from the moment I decided to move to San Francisco.

So I packed all of my possessions into the back of my old Honda Civic, and set off for to a city where it turned out I couldn’t even afford my first month’s rent. It was a risky decision, but finding a way to pay the rent is what ultimately led us to blow up a few air mattresses and rent out our living room to three strangers who needed a place to stay for the weekend. We called it the AirBed and Breakfast, an idea that eventually became Airbnb.

In our society, we’re conditioned to avoid taking risks at all the wrong times. Right after college, we’re told to do the safe thing, check all the right boxes, and keep our heads down. It’s assumed that once we find our footing or get a stable job, then we can try to swing for the fences.

But that’s not how life works, and it’s the wrong way to think about risk. Inevitably, things change as you get older. You might start a family. You might run into unexpected obstacles along the way. And with each day that passes, taking risks will feel scarier, and seem harder, than ever before.

So my advice is, don’t wait. There will always be plenty of reasons to play it safe. But more often than not, the most exciting times in your life will be the times when you take a risk – when you follow that gnawing feeling in your gut instead of the safe, cautious path suggested by others.

For me, it’s made all the difference.

Brian Chesky is CEO of Airbnb.