I think what so young did is a coping mechanism. He didnt really understand how to Cope with sadness and stress. Especially since his painest memory always have to do with pain. Aka, he always get beaten up. The sad thing is, he started to feel comfort in being beaten up. Because when he feels pain his feeling melt away, everything melts away. But the problem is, he is using tae-sung to harm him. While tae-sung want to adore him. This shows how soyoung still saw taesung as someone who can and will give him pain.
I think what so young did is a coping mechanism. He didnt really understand how to Cope with sadness and stress. Especially since his painest memory always have to do with pain. Aka, he always get beaten up. The sad thing is, he started to feel comfort in being beaten up. Because when he feels pain his feeling melt away, everything melts away. But the problem is, he is using tae-sung to harm him. While tae-sung want to adore him. This shows how soyoung still saw taesung as someone who can and will give him pain.