Short dumb down answer he's got mental issues he needs mental health he's never received mental help and the one person that showed him love sadly he abused and pushed away because he was never taught how to love and it is not as simple as what everyone thinks emotions are complicated and humans are complicated and human beings do messed up s*** when they've been through messed up s*** it doesn't make it okay but that doesn't mean showing a lack of empathy is okay either any person who can even look at a bad person and show a lack of empathy they themselves do not truly understand what it means to be empathetic he is learning from his mistakes because someone finally showed him kindness after he's been many years not being shown what he was given by Dan he did not know how to process it and he's finally learning from his mistakes aka the dudes only human