Maybe you’re one away.

I got fired from the first three sales jobs I ever had. By the third time I got canned, I was convinced I sucked at sales. What else was I supposed to think?

I’d started my career in pharmaceutical sales, mostly because I looked up to my father and that’s what he had done his whole career. But here I was, three jobs in, with three terminations to my name. At that point in my career, it felt like I had enough proof to reach a reasonable conclusion:

I’m not very good at this.

Then I took a fourth sales job at a 10-person NYC startup called ZocDoc.

On my very first day in the field, my boss, Ryan, and I spent about eight hours running around Manhattan trying to see if we could sell the service to some local doctors.

By 5:30 p.m., we were both pretty cooked. But instead of calling it a day, Ryan and I stood outside in the cold on our BlackBerrys desperately trying to find another doctor’s office we could call on before we went back to the office empty-handed. With some luck, I stumbled upon a listing for University Place Orthopedics, around the corner from where we were standing in Union Square.

We rode the elevator up to the eighth floor and noticed there was a sign taped up in the waiting room welcoming a new surgeon named Dr. Salil Gupta. So, I made my way to the front desk and told the receptionist that I had a service that would help new patients find and book Dr. Gupta. After a few moments, Dr. Gupta arrived at the front and waved for us to follow him.

I sauntered back, ready to be a spectator, assuming Ryan was going to handle the conversation. But right before we sat down in the back hallway, Ryan nudged me in the ribs and whispered, “This one is all you, man.”

So I went for it. I asked Dr. Gupta as many questions about his practice as I could think of. Then I connected what he told me back to ZocDoc, explained how I thought we could help meet his needs, and asked him if he’d like to sign up.

“I never buy on the first pitch,” he said, “but the price is right, and I think this could be really good for me.”

That was it. It took maybe 30 minutes. I’d just made a sale on my very first day in the field, after three straight jobs that had convinced me I couldn’t sell anything.

I remember thinking to myself, “Holy shit, I can do this!”

And then I kept doing it. Within a few months, I was selling more doctors than anyone else on the team, and the “I suck at sales” story I’d been telling myself for the last few years started looking pretty silly.

There are a million reasons why those first three jobs didn’t click for me. I was immature. I was definitely inexperienced. And I definitely didn’t care about the products I was selling.

But ZocDoc was different. The people were brilliant. The product was something I believed in. My peers were hyper-competitive. And New York City in 2009 was absolutely electric. A perfect intersection of changes that led to a completely different outcome for me.

The truth is that I really did suck at those first three sales jobs. But I took those three bad experiences and turned them into proof that I was incapable of selling.

Then ZocDoc changed everything around me, and I got a completely different result.

Before you decide you’re bad at something, make sure to change the conditions.

Of course, that doesn’t mean every failure is some secret evidence that you’re going to be great one day. But there’s a big difference between “I’m not good at this right now” and “I’ll never be good at this at all."

Sometimes the problem is simply your maturity, experience, environment, boss, product, people around you, or how much you care about what you’re doing. There are a million potential reasons why what you’re working on now just isn’t clicking. Sometimes you just need one more attempt under some different conditions before you know what you’re actually capable of.

I almost left sales completely because I thought I’d proven how bad I was at it.

Luckily, I gave it one more shot. And on my very first day in a new city, in a new job, with a new boss and a product I actually believed in, I walked into a doctor’s office and asked him to sign up. When he said yes, all of that “proof” of how bad I was faded away.

So think about something you’ve tried a few times that hasn’t worked. What happened, and what did you decide it was proof of?

Maybe you'll never be good at it. Or maybe you simply haven’t changed the conditions yet.

I thought getting fired three times meant I was terrible at sales, and always would be.

Turns out, I was just one job away from a brand new story.