seems like a plot/writing convenience situation more than anything imo. narratively, if they've all lived in the same town or area since childhood then they would naturally remember something like that, though i can't remember if this is the case for the people in this school. if it isn't the case, then the author probably just wants to draw attention to both how enigmatic and tragic minyoung is in the eyes of others, and how, on top of his beauty, it really draws people into his snare.

"car accident genius orphan" words that have never been strung together consecutively in history