Everyday Lee Barrett has to deal with the grief caused by one moment of madness.
On May 10, 2014 his son Connor, a young father, was stabbed to death at a house in Hemsby, where he had gone to DJ for a 21st birthday party.
More than three years later, his dad says the pain of his loss is harder than ever to deal with.
He sat through the trial of his 20-year-old son's two teenage killers and listened to every last detail of what happened that night.
But one question remains.
'Why? Why did it have to be Connor? Connor was doing what he loved and that was DJ-ing,' he said.
'We have a life sentence. It is something I will never get used to. I will never get used to the idea he is not here. It breaks my heart. I still can't believe he is not here. I miss him so much. He was a star. People say it will get easier over time. I think it gets harder. It has got harder for me.'
One of the boys convicted of killing Connor, Ayomindy Bile, was just 15.
The other, Jesse Quaye, was 18. Both were from Yarmouth and they were jailed for 15 years each in 2015.
At the time he killed Connor, Bile was on bail for possessing a kitchen knife just a month before in the town.
'Anyone who is carrying a knife is doing it for a reason - that is to hurt someone,' said Mr Barrett, of Trafalgar Road. 'Kids have to realise what they are doing. They are destroying lives of so many people around them.'
See also: Huge rise in blades on Norfolk's streets reveals growing knife crime problem
Connor's son Ashton is now five, too young to know what really happened to his daddy, but old enough to remember him - and miss him.
'There will come a time when we sit with him and tell him,' said Mr Barrett. 'He misses his dad every day. They were inseparable.'
It has had a huge impact on him and his family but also changed the way he sees things in smaller ways.
Mr Barrett, a decorator, went for a walk with a friend soon after Connor's death and was shocked to see a row of knives in the window of a local fishing shop which he had never noticed before.
A recent storyline in Coronation Street where a character is stabbed with a knife also brought back the pain for him and he had to switch TV channels.
He wants stricter rules over the selling of knives online and more done work in schools around the dangers of knives.
Comments: Our rules
We want our comments to be a lively and valuable part of our community - a place where readers can debate and engage with the most important local issues. The ability to comment on our stories is a privilege, not a right, however, and that privilege may be withdrawn if it is abused or misused.
Please report any comments that break our rules.
Read the rules here