Entrepreneurs are famous for being self-taught business minds who relentlessly learn new skills. We read business books and attend conferences. We seek out mentors and develop new skills. But sometimes earth-shattering lessons — ones we could never learn from a book or a fellow entrepreneur —upend our world. They feel more like catastrophes than education. But they teach us the deepest lessons of our lives.

Over the last 23 years, my business partner Bill John and I have built a teambuilding company called Odyssey Teams, and developed a well-recognized brand in our industry. We differentiated ourselves by incorporating service projects into the classroom. We called it philanthropic teambuilding and the term stuck. To date we have given away about 20,000 bikes and about 13,000 prosthetic hands that had been distributed in more than 74 countries.

This success meant a lot of travel, flying across the country to deliver corporate training events. Last year, I was off on another business trip, driving to the airport to catch a 7 a.m. flight to Milwaukee to deliver a keynote speech to 1,000 Northwestern Mutual employees. I was living my dream and, frankly, at the top of my game. A slight hint of arrogance had developed in me as I experienced a level of financial and personal success I had only dreamed about as a kid.

I was still drowsy from the early hour, and I rubbed my face to keep awake. Then, while running my hands over my neck, I felt a strange lump on the right side of my throat. I immediately flashed back to years earlier when a friend of mine described the day he discovered a lump in his neck and it turned out to be cancer. It was almost totally silent as I sped along at 65 mph. It was just me and my imagination wondering about my fate and calculating how soon I could call my wife.

During the drive, somehow I knew in my gut that something was wrong and a battle I had felt looming since I was a teenager was upon me.

Fighting was not new to me. As a dyslexic kid I fought my way through high school and then through six years of college. I fought my way through collegiate tennis matches, and I fought my way though the early years of my business. My father taught me the value of work and that fighting for something you really wanted is just part of the deal.

My wife is a registered nurse and I called her from my layover in Denver. She was anxious to assess me when I returned from the trip and we agreed to just watch the lump until we got back home from our vacation cabin.

When the lump in my throat did not go away, we followed through with a doctor’s appointment. They ordered a biopsy and days passed as we waited for the results. I had my phone with me and my family and friends knew I was waiting for the test results. When the phone finally rang, my doctor told me it was cancer. I wrote the word “CANCER” on the sheet of paper and told her to call my wife. I hung up the phone and the emotion overwhelmed me. Cancer, cancer, cancer. I wept with disbelief. The time had come, and although millions of people have fought the same fight, I felt alone.

I went home to be with my family. I walked into the house and could hear my 13-year-old and 10-year-old daughters crying in their room. After a long embrace with my wife I peeked in to see my girls. We clung to each other in a way I will never forget. My 8-year-old son emerged from his room to give me his brand of love. I had cancer, but they would all need to go through cancer with me. It scared us all.

The next few weeks were a medical blur — test after test and some hard decisions. I had my tonsils removed and a radical neck dissection. They removed 23 glands and a bunch of neck tissue. The cancer had spread to one of my lymph nodes, and I realized that I was a speaker who might not speak again if things did not go well. I began six weeks of radiation.

Work was put on hold. I was a mess and I leaned hard on my team to make it through. The business was growing, but it would need to go on without my leadership. I had to step back and let go of control. Any gaps in the system, any areas I was holding up would need to stand on their own. It was not going to be easy, but we really had no options, and I was ready to see if they could do it. No matter how much I loved my work I did not have the strength to do anything more than fight for my life.

My wife was my rock. When I could not go on she and the kids carried me. The ego and arrogance from my success? Gone. It was just me, 2,500 calories a day and another 24 hours of fighting. I was stopped. The man who always had enough energy and was always ready to take the lead was being carried.

This defining moment has led to some big changes in my life and in my company. I realized that I had way too much of the company on my back, and I was not creating independence or accountability within my team. Many hard conversations came my way following my treatment and I can now see the gaps in my leadership that had been exposed in my absence. Today, my business partner and I are creating independent yet interdependent employees driven by the mission and values of Odyssey Teams, and not just by me. For things to grow bigger than me I needed to learn how to get out of the way more and empower people.

I could tell you about radiation and the after effects of the treatments and issues I am still dealing with today, but honestly, who cares. I am 47 years old, six months post-radiation, and 15 pounds under my normal weight, but I am alive. To really get started, I had to be stopped. I am cancer free and I am a better man, husband, father, employer, speaker and friend. It is not about me anymore or what I can accomplish or whom I can impress or what I can get done. I am temporary. But I can create and contribute to things that can’t be stopped by cancer, things that will live well beyond me.

-Lain Henlsey, Chief Operating Officer of Odyssey Teams