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Sitting in Terminal C at New York’s LaGuardia Airport six months ago, I opened an email from a policy institute where I had applied for a fellowship. For months leading up to the day I submitted my application, friends who were already fellows in the program told me there was no question I would be accepted. Combining my military and work experience, I, too, felt as though I were a great fit.

I helped to start and run an organization that today has grown to nearly 1,000 campuses, played a role in the passage of the post-9/11 G.I. Bill, and has directly and indirectly impacted the lives of over one million veterans. I thought my application stood on firm ground.

But as I read the second paragraph of the note, I learned my friends and I were wrong.

Related: 6 ways the military can overcome its fear of failure.

“We regret that we cannot offer you a place in the 2014 class.”

I was in shock, and my first thought was to send an email or to make a phone call to see if the rejection was a mistake. The second reaction was anger, as I thought the time I spent on the essays and application was for nothing. Then I started running through all the potential areas where I could have gone wrong.

Was it because I did not submit the optional letter of recommendation, even though a close friend sat on the board? Was it because during the interview I appeared too calm and may have given the impression I didn’t care? Was it a wrong response in one of my essays?

It very well may have been one of those reasons, all of them, or something else. But as I sat there I suddenly realized I did not walk on water. For too many years, I had succeeded in most everything I aspired toward. I looked at my last 10 years, searching for an example of failure, and until that moment, I was at a loss. A month later I had another failure, this one in my personal life. From these combined experiences I started to evolve and better understand where I exist in a world that is much bigger than me.

Harvard Business School professor Deepak Malhotra summed it up best in his remarks to the school’s graduating class of 2012. “Humility and confidence are not enemies,” he said. “They are best friends. If you have more of one than the other, you are in trouble.”

Clearly I was in trouble. I was in trouble because I was also considering applying to NYU Stern, Harvard Business School, Columbia Business School, and others. At that point, my approach to these applications was similar to that of the fellowship application: I thought it was a sure thing.

Looking back, the application numbers behind the top MBA programs made my perspective even more troublesome. Consider that Harvard accepted only 915 of the 9,300 candidates who applied. The average grade point average at Columbia was 3.5, and the average Graduate Management Admission Test  score for NYU Stern last year was in the 94th percentile — and I fall short in both categories. The perspective I held four months ago was woefully diluted and thankfully I am a different person today as a result.

Through those experiences, I re-evaluated myself and realized something — failure is the greatest educator. Through failure comes humility, and humility allows understanding and perspective. Without failure, you cannot fully understand yourself nor develop as a person. This experience provided a brutal dose of humility. As a result, my approach to business school applications is quite different today, as is my approach to the world and my openness to learning from others.

Delivering Dartmouth’s commencement in 2011, comedian Conan O’Brien said it best:

“Through the good and especially the bad, the person you are now is someone you could never have conjured in the fall of 2007,” he said. “Your perceived failure can become a catalyst for profound reinvention.”

There are those who have not yet experienced failure, and still believe they cannot fail or falter, but it will happen. If you are not prepared, the effects can be damaging. But with an open mind, and through a search for understanding, you can evolve, develop and become a more grounded person.

My life is drastically different than it was several years ago, much like my view of the world has changed immensely since opening that email at LaGuardia just four months ago, and I’d like to think I owe it to my perceived failure, which has become a catalyst for my reinvention.