Thump.

There is a strange sound emanating from the hallway. It’s more of a series of sounds, of thuds, punctuated by an odd, louder noise. The hallway is narrow, not much room for a five-year-old to create too much havoc. I close my eyes, and as I try to visualize the corresponding sequence of events the rhythm is interrupted by a much louder sound and the house shakes. A child has fallen against the wall. I listen intently, but no one is crying. After a brief pause, the sounds continue.

Thump.

Once more, the house shakes. He has hit the wall again.

I want to give him space, but my curiosity is getting the better of me. What are these noises? His twin brother, Oliver, is outside with his dad, so it can’t be some crazy new game of slam-each-other-against-the-wall.

“I’m okay, Mom,” he calls out, as if to reassure both of us, but his voice is thin and quivers slightly.

The sounds continue.

Thump, thump, kerthump. Thump, thump, kerthump. I tiptoe to the hallway and stealthily peer around the corner. As soon as I see him, I feel the hot sting of my tears and quickly put my hand over my mouth. I know what he is doing.

He is hopping on his left foot, his better leg. He is very unsteady, teetering as if he is riding an invisible unicycle, with his arms spread like wings. I see that they are serving double-duty, not only helping him to balance but also to right himself by pushing against the wall if he leans too much to one side or the other. I marvel at his ingenuity—our hallway is the perfect place for a five-year-old to practice hopscotch.

One foot, one foot, both feet. Thump, thump, kerthump.

But then he falls—kersplat!—his left leg and both his arms failing him. In an instant, he is up and the cycle starts again.

He has been at it for a while, and he will keep plugging away until he is satisfied. That is his style. My son, Victor, does not know that two words, cerebral palsy, hang around his neck like off-set ballast. His arms and legs are stiff, and his balance is precarious, at best. He falls a lot; he has to sit to get dressed; and he is much slower than other kids on the playground. You can see in his face that every movement is a carefully constructed orchestration.

Born at twenty-six weeks gestation, almost four months early, he and his twin have already endured more than a lifetime of hardship. But it was Victor who came home from the intensive care unit with a twisted right side. Ever since, he has struggled to do so many things that we “able-bodied” people take for granted.

However, what really separates Victor from almost everyone else is his sheer determination. He doesn’t understand “can’t,” only “try harder.” And so he will practice and practice and practice, long after I can feign interest in continuing. His doctors and therapists shake their heads and smile in disbelief at his progress, but the credit lies with Victor. In the beginning, I helped out a lot more, but now he only allows me to show him once and then he will take it from there, thank you very much.

If we are running late, I can try to speed up the process, but it will be to no avail. “I want to do it,” he’ll say with surprising force for such a small body as he snatches his sneakers from my hand. God forbid I manage to distract him long enough to slip on his socks; time will have to stand still while he takes them off and puts them on again—by himself. And so we are often late. There are some things that you just have to accept.

I often wonder if Victor knows he is different, although, thanks to his absolute persistence, what physically separates him from his peers is getting increasingly harder for the untrained eye to see. Is his tenacity a reflection of his stubborn personality (no idea where that came from) or does it derive from his own observation of his limitations? Regardless, when Victor decides that he will do something, he simply does not give up until he has mastered the task or at least achieved a close semblance.

And today he wants to play hopscotch. He saw some older girls playing at the schoolyard, and he loves older girls, so he will be in the hallway for as long as it takes. Last year he spent weeks launching himself from our front steps so he could learn to land on both feet like the other kids. He is now the undisputed Frog King.

Thump. Thump. Kerthump. Thump, thump, kerthump. I feel it in my chest as if my heartbeat depends on each tentative hop.

To stand by and do nothing while your child falls and then falls again is torture, but I cannot look away. I am his mother, and it is my job to bear witness. I am simultaneously transfixed, awestruck, and filled with pride by both his effort and his success.

The sound of his voice whisks me back from my short reverie and the hallway slides into focus. He doesn’t stop as he speaks; there is no time for that.

“Mom, look.” Thump. “I can.” Thump. “Hopscotch!” Kerthump.

I smile and fight back the tears. “Great job,” I manage to squeak before hurrying back to the kitchen, where I dissolve on the spot. His spirit and willpower never cease to amaze me. And I understand that I am a better person for knowing him.

The next day, we go to the school yard, and for an hour that could have lasted all day, Victor hopped up and down the playground on his left foot, with both of us wearing smiles of sheer joy and my heart bursting at the seams.

Thump, thump, kerthump. Thump, thump, kerthump. A week later, the noises start again. I sneak over to the hallway. He is now working on his right leg.

Victor may have cerebral palsy, but cerebral palsy does not have Victor.

Jennifer Gunter is an obstetrician-gynecologist and author of The Preemie Primer. She blogs at her self-titled site, Dr. Jen Gunter.