You walked stealthily through the trees, it's an easy way to distract yourself after seeing 2 people die in front of you. You were never very mature, but you were undoubtedly traumatized after seeing 2 men dead and literally exploded in the river; A new trauma added to your memories about this place.

You climbed to the top of a mountain, then you saw Kosuke sitting on the edge of it, if it weren't for the blood on his face and clothes you could swear that he was a "calm" boy.