He must have had to put on quite an act and now they dare come back into his life at the academy and act like they had such a great friendship. Looks like they thought it was great for them, but it sucked for him.
I Know exactly how you feel but in high school YW was like the most popular guy in all school so don't know if he really felt that uncomfortable with the rich kids by then but probably like you said was one of the reasons he found so easy to cut all tights with them
I feel so bad for him. He's the outsider and now they make this accusation. I wonder if this is why he felt uncomfortable with the rich kids and found them easy to cut off (SiWon, Eldo)--they don't get his struggles, he can't go along with the gift-giving and he doesn't eat what they eat or go on trips like they go. It's just too effing stressful to try to fit into that.
My family was very poor, and I always, even to this day, feel ill at ease at anything fancy or going to soemone's fancy house. I always feel like I do not fit in.