Video report by ITV News Anglia's Andy Ward
My vision just completely went and the whole left-side of my body went numb.
When Bobby Copping went up for a header in training, he could never have known his life was about to change.
After hitting the deck, he momentarily lost the majority of his vision, the entire left-hand side of his body went numb and he suffered a mini seizure.
He was taken to hospital where he spent the next four days, and at that point, hopes were high that it was just a one-off.
But it wasn't.
After working his way back up to full fitness, five months down the line, the same thing happened again.
This time it was during the warm-up of his comeback game for Peterborough United's under 23s.
Having now realised that there was clearly an underlying problem, Bobby had to make what he himself calls the "hardest decision of his life" - the decision to give up the game he loves at the age of just 19.
It was the cruelest blow imaginable for a player who had just started to break into the first team at Posh, and was regarded as one of the club's brightest young talents.
Watch an extended interview with Bobby Copping
"I was probably sat in my room for probably two weeks straight, in the dark, curtains closed, just eating rubbish all day thinking about it because at that time my life had come crashing down," he told ITV News Anglia.
"The hardest moment was definitely calling my mum. Hearing my mum cry on the phone was definitely the hardest part."
Bobby sought advice from one of the top brain specialists in the country, and was diagnosed with trauma triggering episodes.
To this day, he's still experiencing memory loss, headaches and car sickness, but doctors are hopeful that by withdrawing himself from the sport, he will still be able to lead a full and healthy life.
Like many young players, Bobby had been heading the ball since he first joined Norwich's academy at the age of eight, and although he doesn't know for sure, he suspects that may have played a part in his injury.
The potential links between heading the ball and dementia have been under the spotlight in recent years, with former Norwich striker Chris Sutton, who recently lost his dad Mike to the condition, among those calling for change.
Sutton recently teamed up with the Daily Mail newspaper to publish a seven-point charter calling for more action to be taken, including the introduction of concussion substitutes and for heading to be limited at all levels in training.
Concussion substitutes have now been introduced in the Premier League on an initial trial basis until the end of the season, and Dr Michael Grey, who is leading a study at the University of East Anglia which is testing former players for early signs of dementia, believes that should just be the start.
He said: "We need a better mechanism for the graded return to play protocols that are used in professional sport and the academies, I would really like to see that in schools.
"I would like to see medical professionals who are not team doctors, to be educated in graded return to play protocols so that type of system is available for everyone."
Bobby, who was born in Essex but grew up in Dereham in Norfolk, has now been offered a business role in Peterborough's academy which will be key as they work towards upgrading their youth set-up to category 2 status.His story has touched the footballing community, and Bobby has been inundated with well-wishes from a number of high-profile players.
In fact, England captain Harry Kane even sent him a signed shirt, while Chelsea star Reece James has offered to take him out for a meal once lockdown is over.
"Harry Kane reached out to me and sent me the shirt, Reece James has reached out to me," he said.
"They don't have to do that but there is some really, really nice people out in the world and that's helped me a lot."
Now, Bobby is hoping to offer some help of his own.
He has an ambition to set up his own foundation, which would provide support and guidance for young players going through a tough time.
"If I can help just one person then I'll be happy," he said.
"Life can change so quickly and for every young player, I'd say just be grateful and take every training session and game as it's your last because unfortunately I've found out what that's like, and it's not a nice feeling."