What do you wish that everybody knew?
Hanlon's razor says "Never attribute to malice that which is adequately explained by stupidity". Hanlon's razor cuts infinitely deep. I have never found a situation in which, if you look deep enough, the evil of someone's actions could not be adequately explained by them not having enough knowledge* about how their choices would (or do) affect others and, in the end, because of that them too. *Knowledge in all of its manifestations, not just in the "declarative memory" sense: experiences, feelings, perceptions, empathy too are all knowledge.