A big problem with the way history is taught is that we aren't taught the full context of just how awful life was back then. We're (Sweden here) taught the names and lives of an awful lot of kings and how much they murdered people but we never get the perspective of serfs and tradespeople. They don't matter, because workers don't matter to this day.
Make education leftist, make people understand the class struggle that goes on to this day. Teach kids to draw parallels between oppression back then and oppression now.