Responses
You can't say that. It's just people deal with trauma differently. His conducts are more self destructive, so it appears impulsive and "childish". But when he got into school, he sacrificed his happiness, restraining himself, consistently looking for ways to make haesol happy, things that caregivers are supposed to do, take care of a child. It's not necessarily a good thing. Just as a response to trauma is being too mature or your age, the other side of the coin is being immature or your age.
Dude he is definitely a kid in the head he never got to live to a proper childhood but unlike haesol it seems that it's possible to get some of that childhood whimsy out.. haesol didn't have a childhood and was forced to mature, he on the other hand didn't have a childhood but never really matured either so he is like a big baby.. especially with how he has very little control over himself and seems used to listening to what others tell him, he barely did anything behind Yeonwoo's back and listens to him like he is his mom! I think this is gonna be relevant...