I DID not want to think about dying. I certainly did not want to think about myself or my loved ones being cut up after death. Ugh. No thanks. So I was squeamish about anything to do with organ donation, as so many of us are for understandable reasons — until I met Sue Burton.

She is a costs lawyer from Grantham, Lincolnshire, who told me how her son Martin had died in the summer of 2003, at the age of 16. Sue woke up in the night to find him standing in the doorway of her bedroom, before he fell forward on to the bed, unconscious. Martin had suffered what the doctors called a catastrophic bleed to the brain, as the result of a burst blood vessel. It could not have been predicted or prevented.

A consultant told Sue that her son was brain-dead, and then asked almost immediately if she had considered organ donation. I thought that that was a brutal thing to do, until she told me, no. “In another hour, I couldn’t have given consent. The grief had got me, and I didn’t even know my own name.”

Martin, aged 14,

Sue knew that Martin wanted to be a nurse. Somehow, in that terrible moment, she found a sliver of comfort in the idea that her son might save lives. And he did. His liver saved a 34-year-old man, Andrew, who was able to see his children grow up.

Martin’s heart was taken across country by road and air in a race against time and put inside another 16-year-old, Marc McCay, who had been struck by a virus and could be saved only by a transplant. Marc’s mother, Linda, had even begged the doctors to take her heart, but of course they couldn’t do that.

There is much more to this extraordinary story, which I tell in my Radio 4 series and book The Boy Who Gave His Heart Away (Harper Element) (Books, 14 July 2017).

I was in the room when Sue met Marc again, 13 years after the transplant. I saw the mother of the boy who was lost reach out to touch the boy who was saved. She put her hand on his chest and felt, fluttering away under her palm, the rhythm of the heart that had been born in her womb, and that had kept her son alive for 16 years. Now, here it was, beating inside the body of another boy, who had become a man.

That was such a moving moment. Now I was personally involved. And, later, Sue forced me to face my own feelings when she asked: “If a son or daughter of yours needed a heart, wouldn’t you want them to have one?”

I said yes, of course. I would even offer my own, as Linda did. Sue smiled. “Then how can you possibly deny that to another parent and child, when you will be dead anyway?” I had no answer to that, and signed up to be a donor the next day. Until the system changes, I would urge you to do the same.

Cole Moreton is a writer and broadcaster, and a patron of the charity Donor Family Network.