Readers love mysteries and will endlessly work to justify or figure out the details. Whereas if you pedantically point out every little pointless factoid they’ll quibble with you and you’ll probably get some things wrong, and you’re probably not a:
Biologist, and an Historian, and a Geologist, and an Astrophysicist, and a Vulcanologist, and an Economist, and a Sociologist, and an Artist, and a Psychologist, and an Architect, and a Philologist.
This isn’t to say that you can’t do deep worldbuilding and think about the facts of your world, but one safe option is not to say. Then nobody can really come along and prove you wrong.
This also lets you endlessly retcon things, especially valuable if you’re writing a series.
endlessly retcon things
In addition, if you’re using the omniscient narrator, then that narrator knows, but if you’re writing from the pov of a character, and in particular deep pov, not that hovering behind the eyes omniscient narrator pov, then characters frequently won’t know relevant facts about the world. In fact, through most of human history, people didn’t know quite what was going on, and empiricism and the scientific method weren’t invented until fairly recently (and granted, even now we may be wrong about what’s going on).
There’s also the intriguing idea of writing a character who thinks they know but is frequently wrong. They can be both wrong within their own worldview and wrong within our worldview.
For example, where are the characters that think they know how magic works and are wrong? Almost invariably bildungsroman and coming of age wizard and fish out of water transported to a magical world who is invariable magically gifted stories feature mentor wizards who know practically everything about magic, and teach their pupil, and the pupil learns and rebels and is punished then studies up and truly learns and does magic the right way and is rewarded.
Maybe occasionally what everyone knows about magic should be wrong. Maybe spells don’t work the way they think. Maybe it truly is a demon granting you the power to damn your soul.
You’ll probably want to tease your reader with some snippets of how things truly work, and techniques like lying to the reader are dangerous, so you’ll want to encapsulate the mistake in some foreshadowing or uncertainty. There’s a reason that “it was all a dream” is now so hated and railed against in writing advice. But if the characters experience the shock and dismay of thinking they know how things work and finding out they are wrong, and they are a sympathetic character, then your reader will probably be hooked, and also filled with another dose of wonder.
You can also, if it appeals to you to spread about facts, use fictional non-fiction. Frank Herbert used this method to introduce chapters and do some of his worldbuilding in the Dune novels. There are entire fictional works that take place within this milieu, such as Dictionary of the Khazars and A dictionary of Maqiao.
In my opinion, one of the most humanizing things about characters from the past, and one of the things that can make them seem the most real and sympathetic, is to see what they mistakenly believe to be true. Though in a secondary world all kinds of things can be true, which we might think, from our rationalist perspective would be false, which can lead to an entire level of kayfabe within a literary work.
But all in all, I think that even though you might do hours and hours of worldbuilding, chronologies, and mapmaking, it’s best to keep the actual writing mysterious.
keep the actual writing mysterious