I'M STILL ALIVE'S TheoryEdit
My guess is he grew up in an abusive family. He had no siblings and not very many friends. His mom was always drinking and yelling at him and would tell his dad to beat him and his dad was a man who has been to jail several times for bar fights, theft, abuse and being drunk in public. Ben most likely lived in the basement in a small gloomy room and would lock himself away and play on his game consoles or sleep. His favorite series would be The Legend of Zelda. He probably got the Majora's Mask game from a friend or a cousin who no longer had interest in it. He would play it as long as he could and shut away the torture from his own family.
One night when his parents got into a fight, his dad took him unexpectedly and brought him out to a lake and didn't say a thing for the whole car ride. He threw his son into the lake and held him under until he was surely dead. He abandon his body there and got rid of all his stuff that night, including his games. Ben's soul was already in the game when his father was ridding his stuff and he was trapped in the cartridge for a very long time. His father threw Ben's belongings out on the road. That night, the old man picked up the worn out cartridge and put it up for sale in the morning.