Qiao Feng tattooed at the age of one, and stole and killed at the age of seven. Why did Jin Yong write this?

Qiao Feng and Xiao Yuanshan in Eight Dragons know each other. Judging from the wolf tattoo and appearance, the Khitans have had tattoos since they were one year old.

Qiao Feng once told the injured Ah Zhu about an incident when Qiao Feng was a child. In order to treat Qiao Feng's father, his mother and seven-year-old Qiao Feng took out the only six hens and a basket of eggs at home and spent four yuan to see a doctor, but the doctor didn't want to go into the mountains to see his father because he had no money. Under the mother's pleading and pulling, the doctor also flatly refused. On the way home, Qiao Feng stole a knife, which was originally his plaything. He didn't want to kill anyone.

When I got home, my mother's four silver coins could not be found. Qiao Feng's knife became the reason why Qiao Feng was suspected of stealing money. Qiao Feng felt wronged, ran dozens of miles into the city at night, slipped into the doctor's house from the dog hole, and killed the doctor with one knife.