So what mistakes have your characters made? What do they do to avoid repeating them or are they oblivious of the need for this? What mistakes has your fictional world as a whole made? (I'm thinking internally and externally here - what mistakes has your world made in looking after its own environment? How does your world get on with others it has contact with?).
Do your characters study history? Does the world you've put them in remember its history as we tend to do with things like Remembrance Sunday and so on?