The Boston Marathon is one of the most amazing events on the planet.

I didn’t get the performance I hoped for this year as the defending men’s wheelchair champion, but my personal sense of loss was overshadowed by the real loss and tragedy I watched unfold only a few hours later.

I wasn't afraid, but the panic I saw on others' faces as they rushed away from Copley Square after the bombs went off broke my heart. Many people were hurt, and three were killed. It was just horrible.

The city of Boston is feeling loss. The loss of innocent people who were there to celebrate and support loved ones. The loss of a day that is usually full of celebration, happiness, pride, and an amazing, positive energy that ripples over more than the 26.2 miles of the course.

Overcoming adversity, challenging ourselves, celebrating life, accomplishing amazing feats, becoming a part of history, taking part in tradition. These are just a few things that come to mind when I think of what the Boston Marathon stands for. It's why people run it, with one leg or two, or none, or blind, or in wheelchairs, or even pushing someone else in a wheelchair. The participants get it, as do the spectators, organizers, sponsors, volunteers and many more.

The Boston Marathon already has everything it needs to recover.

This race is a testament to, and a symbol of, defiance. Even more than other marathons, Boston is about not giving up. Take the story of the legendary "Heartbreak Hill" for example. The name, surprisingly, does not come from the seemingly endless climbing required at the "breaking point" of the race. The term "Heartbreak Hill" was actually born in 1936 after the defending champion, Johnny Kelley, passed Ellison "Tarzan" Brown and mockingly tapped him on the shoulder as he sped by. Brown never gave up and pushed his limits until he beat Kelley at the very end for the win, breaking Kelley's heart.

There are so many more legendary stories. Dick Hoyt pushing his son Rick in his wheelchair. Bobbi Gibb, the first woman to defy the males-only rule and run Boston in 1966. Plus many amazing stories that no one has heard. At this time, we need to share these stories more than ever.

Incredible crowd

My first Boston Marathon was in 2006. It was among the first marathons I ever competed in after training as a wheelchair racer for about five years. I had been training hard on my own, with not many people really seeing all of the work I had put in those first years. I was doing it for me, and to chase my dreams.

I don't even remember what place I came in that year. What I do remember from my first Boston Marathon was one of my nine younger siblings being able to come and support me on the sidelines. That meant the world to me, knowing he was there. It was a tough day, and I had hoped to do better. As I crossed the area where I knew he was standing, I could feel his support.

I also remember as clear as day taking that last right-hand turn before the immediate left onto Boylston for the final straight.  There was deafening cheering from the crowd. For me. I looked behind me to make sure, but no other competitor was near, in front of, or behind me.

I couldn't believe it. For years, I thought no one really got it. What I was doing. Why I was doing it. And then, all of a sudden, thousands of people showing their support and cheering me on. I remember trying so hard not to let a few tears stream down my face, and then putting my head down, partially in embarrassment, but mostly because it gave me an incredible surge of energy to give everything I had to that finish line. I will never forget it.

More memories

Last year, I gained another memory that will last a lifetime.

I had possibly the toughest few months of my life that winter. Everything was seemingly going wrong while training in Australia in January through February. Every area of my life was in a downward spiral. Training, equipment, finances, my relationship, family, team support, health… everything. For a while, my grandmother was on her deathbed with little chance before she eventually recovered.

It was a pretty emotional and tough time. At my worst, I was being checked by doctors in Australia for signs of cancer. Crazy enough, I wasn't afraid. Don't let fear win, I told myself.  I just needed to know what I was fighting and I would fight it. And win. Tests came back negative, and I vowed to put my head down and train hard every day and not care what else was thrown at me.

There was also a little five-year-old girl from Britain, Niamh Curry, who was battling the same type of cancer I had as a child, neuroblastoma, which left my legs paralyzed. This gave me a real reason to move forward, a fire to win that season, for her. I focused on something that mattered beyond myself. I consciously decided to forget about the last two months of horrible training and make the next six weeks of training until Boston the best ever.

I won the Boston Marathon.

In the process, I also broke the record for the world's fastest time, at 1:18:25.

Everyone has their stories, and those are mine. 

So thank you, Boston. You've created memories that will last me until the end of my days. And until then, you will bring me many more over the years to come.

We will continue to mourn those lost, and help those damaged. But we’ll also remember what this event stands for, and keep moving forward.

We won't allow fear to win. We will allow the Boston Marathon to inspire forever.

Josh Cassidy is a two-time Paralympian and the winner of the men's wheelchair division at the 2012 Boston Marathon and the 2010 London Marathon. Follow him on Twitter @JoshCassidy84.