True. I was also thinking that during Jiri's college/HS days, he was at a low point in life because of his self-identity and that's when he met the kind Gu Jeong Ho whom he genuinely fell in love with (and not just a "crush", as Yuri would say it). It's probably why he sympathizes with Jiheon(?), the rumored gay student that dropped out of school, too.
Yeah if it was a simple crush he probably wouldn't have been so hung up over it. He was probably someone that helped him while he was at a really low point in his life. Also he might have become a teacher to help students that are struggling (maybe like to prevent the stuff that happened to him)
I love this so much and I really hope we get to see the development of yuri and have him actually apologize to jiri for his previous actions. I love jiri sm and I think there’s something more behind his depression besides his unrequited love. I feel like maybe his parents were homophobic and disowned him. Also, it doesn’t seem like he has anyone to rely on so he slowly starts to develop this loneliness which might be one of the major cause of his depression. Also, he’s akways helping other ppl but no one ever helps him and when they try it always ends up worse which probably made him closed off and led to his pushover nature.