In Dave Cullen’s book “Columbine” he describes what the principal of Columbine High School went through during the massacre. Frank DeAngelis was shot at by the assailants. He was standing in front of a glass case and he vividly remembers the glass shattering and him falling down in a bunch of broken glass. He was walking to the main office to interview a prospective teacher. The last fact is key.

DeAngelis suffered PTSD something fierce in the years afterward. When he was interviewed by investigators he swore he just got done interviewing a prospective teacher before he was fired upon - remembers details, setting, what they talked about - when in fact the interview never took place. He was on his way to the interview and he got shot at.

Human memory is weird like that.