For many people their trauma hit them differently and they act on them different from others. I'm sure he could've found his old self a better train or thought, but he simply ignored is chosed what was easiest to help him cope with it. That's just my opinion, as a child your first role models are your parents(whoever is raising you). When his mom said she loved him then left him that probably sparked a total different meaning to how he viewed love. Then as he noticed his mom started publishing books Sieon felt when she left him she was more happy because she was finally doing her dream.. & getting through without him. Sieon might feel if he leave those he " Love," they would finally be happy because that was shown to him. Not everyone can define love truly if they haven't encountered/ been involved in it fully.