I've started letting people in my world be confidently wrong about their own history
For a long time I treated my setting like everyone living in it had access to the same wiki I did.
If a war happened 300 years ago, people knew why. If an old fortress was built for a certain purpose, everyone more or less understood that purpose. Different cultures had opinions, but the basic facts were always conveniently correct.
Recently I started messing with that.
One city is proud of a famous "victory" that was actually an organized retreat. A religious festival supposedly commemorates one event, but historians think it started almost a century earlier for a completely different reason. People in one region confidently blame a neighboring kingdom for introducing a crop that archaeological evidence suggests they were growing first.
None of these are huge secret twists. Most will never even be resolved in the story.
But suddenly the world feels much more real to me because people inherit bad information, simplified stories and local myths just like we do.
How much incorrect history do you intentionally put into your worlds?