Piece by piece: a heartfelt memoir of a boy who built his prosthetic arm from LEGO

Published: November 15, 2022

In November 2020, we featured David Aguilar Amphoux in ‘How to build a STEAM generation’, issue 6 of Futurum. Two years later, David has written a memoir alongside his father Ferran about his journey to becoming a role model for millions worldwide

Not all of us will know what it is like to live with a disability, but all of us will have experienced challenges that seem insurmountable at the time. And while we are dealing with those challenges, it can feel as if no one is around to help – as if we must face our battles alone. David’s memoir, co-written with his father Ferran, centres on his experiences of living with a disability and his incredible journey, from building a prosthetic arm from LEGO at the tender age of nine, to becoming an influencer with a degree in bioengineering.

In addition to this, Piece by Piece exposes some of those overwhelming life experiences that affect us all: bullying, heartbreak, grief, failing exams. Here, we publish extracts from this memoir in the hope that, just as David has, you will discover that you are not alone and that all challenges, however big or small, are surmountable. We also hope that, like us, you will be inspired to take risks and follow your dreams, no matter what they may be or what anyone else thinks. As David says, “The true disability lies in believing you can’t achieve anything.”


I’ve often been asked what it feels like when you’re missing half an arm. And the truth is, even now at twenty years old, I still don’t know. What do you feel if you’re missing a finger? […] What do you feel when you’re missing the eleventh finger? Whoa! You don’t know what that feels like, right? I count to five you count to ten. I am not missing anything. Neither are you.

And if you are a part of that small group of us who don’t reach ten, like me, then you’re not missing anything, either. Really. At first you don’t see it, because your entire life you’ve heard the word without or been told you’re “missing” something. Well, I’m here to tell you: You’re not missing anything; in fact, you have a surplus.

A surplus of opportunities.


“Hey, David,” Jordi greeted me when I arrived. I’ve already told you he’s been on my case from the beginning. I was surprised he’d say hello, he was usually a jerk to me.

“Can you lend me a hand with the math homework?” he asked, stretching out his right hand. As you can see, it took 0.7 seconds for him to act like usual – that is to say, like a complete and total bonehead.


“Oh, sorry!” Some giggles could be heard from our classmates. “I guess I have the upper hand on this one.” And the chuckles broke out.

It’s hard to believe that people still get on your case or sell you short, even if you do great things. Jordi was in my class when I’d build the first prosthesis; he knew what I was capable of. […] But what I want to explain now is: I barely cared at all about his opinion. One of the biggest lessons you need to learn in life is that reaching your goals, whatever they are, is what’s important – but you need to do it yourself.

David with his father, Ferran.
© Jose Sanchez, Foto Estudi La Seu
The making of Mr Hand Solo, a documentary.
© Ferran Aguilar
National Geographic Spain featuring David.
© Pau Fabregat


She wrote a lot of things. That yes, she had a good time with me, but ‘it’ (my arm, or lack of arm) gave her the “creeps”. That her friends “laughed at her” (no, Marta, they laughed at me; maybe now you understand that better), and she just “couldn’t”. That she felt bad. That we were friends. That she hoped I forgave her.

Without knowing how, I managed to say goodbye and archive the chat without blocking her.

Returning home, I felt like the stupidest creature on the face of the earth.


Tears slid down my cheeks like silent, unceasing waterfalls. They sprang from a well of pain, that, sealed off until then, now seemed to find its way out. I had cried on only three occasions in my life up till then, and my abuela’s funeral was, without a doubt, the worst of all.


With all the overwhelming love and support that had reached me since I’d gone viral, I couldn’t help but remember with every day, and even every hour, my abuela Basilia. More than a year had passed since she’d left us, and although I missed her affectionate caresses, embraces, kisses and words (her voice diluted in my memory like the steam off a hot chocolate – sweet until the end, bitter when it’s over), her love remained around us like a warm blanket.


It was then that my grades started to plummet until they settled lower than five in all my classes. Even physics and math. Even Catalan, Castilian, history. The heat arrived with increasing violence, but I still wore long sleeves and tucked the right cuff into my pocket. My teachers called my parents, and my parents spoke to me. I tried, studied and struggled to concentrate, but my head rejected anything that tried to enter it. There was no room left. The wound from Marta’s betrayal kept bleeding. The well of grief my abuela had left behind seemed impossible to drain. In the end, I had put on short sleeves because the heat won, and I had to repeat five subjects.


Repeating a year was an unexpected tributary that opened before us, and while it seemed better to avoid it, I wasn’t so sure it would be something bad. Maybe it was the path I needed to take. Perhaps in the end, the tributary was in reality the main watercourse, and it would lead me to the sea I was hoping to reach. Sometimes the unexpected holds the biggest solutions in life, and to achieve them, we just need to let ourselves follow the current.

Extracted from Piece by Piece by David and Ferran Aguilar
(Amazon Crossing, £8.99).