Simon Keith is one of the world’s longest surviving heart transplant recipients and one of the only people to have played professional sport after the operation.
He owes the last 30 years of his life to 17-year-old teenager Jonathan Edward, from Newport, who died following a sudden brain haemorrhage while playing football in the park with his friends.
Their story is an incredible one that reveals how powerful and enduring the gift of life from a transplant can be.
Simon, a former professional footballer, was 21 years old and on the verge of playing in the Fifa World Cup when he was given the devastating news that a rare virus had caused his heart to become enlarged and not function properly.
The gifted striker, who was with the Canadian first team at the time, said the diagnosis meant his lifelong dream of representing his country was in tatters.
"I had to watch my teammates all prepare for the World Cup, and it was devastating to know that I wouldn't be able to play alongside them," he said.
While his former teammates were enjoying the pinnacle of their careers, Simon soon found himself struggling to breathe during training.
It also became progressively difficult for him to warm his hands and feet which were often "ice cold" at the end of sessions.
"I just didn't feel myself. My hands and my feet would just go shockingly white," he added.
"I didn't want to 'crush' people anymore competitively. I just wanted to get through practice."
In March, 1986, just months before the World Cup was held in Mexico, Simon was diagnosed with a condition known as viral myocarditis.
Triggered by viral infection, it leads to inflammation of the heart muscle and reduces its ability to pump blood. Clots can form in your heart, leading to a stroke or heart attack.
In Simon's case, the myocarditis caused his heart to fail to such an extent that only a transplant would save him.
"The doctor comes up to me and says 'we've done everything we can'. You need a heart transplant or you're going to die'."
Simon did not qualify for an immediate heart transplant in Canada, and in the USA there was a huge waiting list of 14,000 patients.
But because he was born in the UK he had dual citizenship which allowed him to be put on the UK transplant list.
"Although my heart's function was slowly deteriorating, I wasn't sick enough to qualify for a heart transplant in Canada," added Simon, who was born in the English coastal town of Eastbourne before moving to Victoria, British Columbia.
"My parents, who were desperate to see me added onto the transplant list, decided to move us back to the UK and I was immediately taken to King’s Cross Hospital in London."
After arriving back in the UK, it didn't take long before a "perfect" donor heart was found for Simon.
"I remember the day it finally came. My parents and I were in the hospital, it was a hot day in July and we'd just about given up all hope," he added.
"It was a strange moment, and one I don't think I'll ever be able to put into words. To be simultaneously celebrating and feeling remorse for the loss of someone else's life; it was a complex thing to feel."
In July, 1986, 21-year-old Simon underwent the heart transplant which proved to be a huge success - and within three years he had miraculously returned to playing football professionally in the USA and Canada.
But over the years he became increasingly eager to know who gave him the chance to continue his football career and allow him to become a dad-of-three.
When transplants were carried out in the '80s and '90s donor families and recipients tended not to get in touch with one another.
He added: "I had always been intrigued to find out whose heart I had beating in my chest, and of course I wanted to sincerely thank the family who made the life-changing decision to donate their son's organs."
In 2011, at 46 years old, he set up the Simon Keith Foundation to support children who have had an organ transplant in resuming an active and healthy lifestyle.
More than ever, he was desperate to show his donor's family that their precious gift was having a positive impact on so many other people.
"I noticed that a lot of people were using Facebook to get back in touch with friends and family of years gone by, so I thought 'why not?'
"By that point I was working with a writer to publish a book about my experience, and he managed to track down the family through social media."
It transpired that the heart donor was 17-year-old teenager Jonathan Edward, from Newport, who died following a sudden brain haemorrhage while playing football in the park with his friends.
After contacting the family, Simon, who was now living in Las Vegas, flew back to the UK to meet Jonathan's dad Roger and his best friend Richard Parker.
Simon recalled: "I spent the day with Roger listening to stories about Jonathan, and he even took us to see where he'd gone to school, grown up, and to his final resting place."
Ever since their meeting, the two families have stayed close, with Simon regularly making trips back to the UK to meet Roger and Richard and share his organ donation story with the wider community.
Jonathan's best friend Richard Parker, 49, from Newport, said: "I've become great friends with Simon and his family and now realise what an amazing legacy has come from my friend's passing.
"Simon's son Sean has lived with us off and on over the past couple of years whilst he fulfils his own footballing dreams."
In 2016, Richard and Simon organised a football game, called 'The Match For Life', in Newport which celebrated Simon's 30-year anniversary post-transplant.
He is now one of the world’s longest surviving heart transplant recipients. He was also the first athlete to have played professional sports after having undergone a heart transplant.
Simon is now backing the upcoming British Transplant Games taking place in Newport between July 25 and 28.
It promises to be a "celebration of organ donation", highlighting the health, fitness and wellbeing of recipients who wouldn't have been able to compete without the kindness of donors and their families.