Actually its about two different people
one is a 15 year old boy named jeremy that lived in texas and killed himself infront of his whole class in 1990 (he put the barrel in his mouth while facing the class, hence the lyrics Try to erase this. From the blackboard.) and the other is a boy eddie vedder knew personally in his school daze and had gotten into fights with. One day the boy snapped and shot up his classroom. Eddie said that he remembered hearing the shots from his class (hence He hit me with a surprise left
My jaw left hurting Dropped wide open Just like the day Like the day I heard[ the gunshots]).