In episode 4 - when Dohoe met Juyeong again, he said something along the lines of "I heard you kept in touch with him, you're a great person" and "You should be the one wearing this armband, not me" - these lines explains how Juyeong built a father-son relationship with Dohoe's dad, which is something he didn't have because he grew up with a violent father figure. Maybe in Dohoe's eyes, he doesn't understand how Juyeong can forgive and forget all those pain and violence displayed to them by his Dad.