about deleting the contacts of old buddies - at the reunion they were talking about how they succeeded in their lives and he, who was so popular at school, was doing some shitty work and living in some shitty apartment, so his life wasn't that wonderful as he thought it would be - he was bored and depressed and really not successful, and ashamed, I suppose. That's why he deleted the contacts, he didn't want to feel more pitiful. It happens when life hits us really hard and we only remember how wonderful our youth was, and now there's nothing but shit.
I think we are missing some important clue when it comes to Dohyun's memory. The story has now shifted more towards Sungho's POV and since remembering that they were involved in highschool it has not been made clear what else may have been stirred since then. I had the feeling though in one recent chapter (I forgot which), when Dohyun was given the choice between inserting and dicksucking, he deliverately may have gone against the memory to provoke Sungho, which he was...
maybe he doesnt remember because he felt bad and so pretended that memory didnt exist and because remember how he deleted all contacts of his old buddies . Like hes to run away from someone whos in his school. I dont get the reason to ignore school friends. Maybe over time he just forgot. Or maybe cause he was just playing ..at the beginning he got slapped by a girl meaning he did it with many ppl so its pretty normal thing to him :/ watcha guys think?