Almost four years ago to the day, I was hit by a pickup truck. It took four months to learn how to walk again without assistance, and another three years of physical therapy to undo more of the lingering damage caused by the accident. 

So it meant a great deal to me to compete in the Tough Mudder 10-Mile Classic event last weekend. It’s a mud-soaked strength and endurance marathon that pushes you through mental and physical walls – or makes you jump over, swim through, or climb under them.

One of the biggest walls for me to get over was that I was running the course solo. It started out as a threesome, but my companions dropped out before race day. The 10-mile stretch had its moments of exhaustion and weakness-of-willpower, and a few of those obstacles laid me out flat after losing my grip on a rope or muddy wall. But I powered through and finished within a respectable time frame. Truly, it was an achievement for me. 

I won’t lie, I could barely move my...