Mats Steen suffered a debilitating muscular disease that kept him confined to his apartment - but after his death at age 25 his parents discovered his secret online life that filled him with joy.

Trude and Robert Steen found out the Norwegian man had a popular and fulfilling social life through his personal blog and his online roleplaying in the video game World of Warcraft.

The parents, and sister Mia, knew that Mats would spend hours online using special equipment to accommodate his disability. 

But until his death, his mom and dad believed his life had sadly been a lonely one. It was soon after his passing they began to receive hundreds of emails from strangers who seemed to know him extremely well.

The family learned how their son had found friendships and even romance among the gaming community.

Trude and Robert had believed their son had led a somewhat isolated life, with him relying on a wheelchair to get about after being diagnosed with Duchenne muscular dystrophy, a genetic condition that eroded his ability to move and breathe.

But their minds were about to be blown as hundreds of people got in touch with the Oslo-based family to express their condolences following their son's death.   

The first they knew of their son's secret life came after they announcing his death on his online blog, on which there was an email address for users to contact the family.

Mats parents and sister had been expecting a few replies but were not prepared for the reality as they were inundated by hundreds of strangers writing to them - also, Mats was known by a completely different name: Ibelin Redmoore. 

As Redmoore, Mats had been an avid player of World of Warcraft, an online game phenomenon.

Redmoore was heroic nobleman and monster slayer with Mats controlling his every move, all while sitting alone in an apartment upstairs from his parents in Oslo. 

It was through the gaming platform he had managed to form meaningful friendships and even romantic relationships. 

Redmoore had built up an extensive network of friends over the years and had become known for his kindness and empathy.

Like many parents, Robert and Trude had actually discouraged Mats from spending too much time online and suggested he try to foster connections in the real world.

'We thought he lived, for many reasons, a wasted life. And then we get these stories sharing just the opposite,' Robert began.

'The sad thing is that we were very strong on condemning the time they were spending in that world, and that condemnation was based on a five-minute analysis,' Robert said to The Independent. 

'We did all the right things, and we were so present in our children's lives. With one exception – and that is the digital part of their lives.'

The incredible double life led by Mats has been explored in a new Netflix documentary, The Remarkable Life of Ibelin, due out on Friday.   

The film depicts how online gaming can be a portal to another world; one of friendship and romance and providing something of an escape to those who are severely disabled.   

'In Scandinavia, at least, we feel that we are becoming more and more fragmented. Everybody's looking after themselves and their own causes; we have become extremely individualistic, centered on our own things,' Robert said. 

'These collective solutions that we had some generations ago are gone, in a way. So if this could be one of the messages from this story – the kindness we can bring to a community, to the world – that would be great

'Mats, in his condition, could help so many people without being able to move more than just his fingers. Imagine what the rest of us could do if we put our minds to it,' he added.

The documentary sees a world where online gaming can be a place of opportunity for disabled players.

Using the World of Warcraft archive within which thousands of words of interactions between Mats and his friends were recorded, the film recreates his digital life, using animation in the style of the game and voice actors speaking his words out loud.

Of course, it also leads to a raft of fantasy-character in various shapes and sizes - but this was the world Ibelin was finding - a whole new world in which anything was possible, free from the restrictions his disability imposed.

'It creates environments where physical barriers don't exist, allowing players to interact with each other on an equal footing,' says author Marijam Did who has written about about the impact of video games. 

'Entire communities and livelihoods are crafted within this digital realm. I would always encourage pairing it with physical interaction, of course – too much of anything is not great – but we must de-aestheticise what interaction is.'