Harald grew up in a normal household in Denmark, normal family, normal education. Nothing was out of the average with Harald. Harald liked to fit in with the rest, trying not to stick out. Harald finished his education in 2016, graduating with decent grades.
Harald didn't do much with his grades though, he slowly descended into drug abuse, having used heroin and cocaine on a regular basis. This made him live in the "slums", which also made him get into contact with sly and criminal individuals.
He established contact with Magnus Sharp, who took Harald with him down into the rabbit hole, slowly getting in deeper water with criminality. Magnus established contact with the "The Nordic Brotherhood", which also meant that Harald followed suit.
This contact with "The Nordic Brotherhood" made Harald get drawn into Chernarus, because of the unrest and economic vulnerability.