All Models Are Wrong … But Some Are Useful
Farnam Street (Shane Parrish), after George Box · 2017
"Every mental model is a simplification and therefore, strictly speaking, wrong — the only meaningful question is not 'is this model true?' but 'is this model useful, and for what?' — the necessary caveat on the entire mental-models project."
A model is a simplification that helps understanding — like an architectural model of a building, or a map of a city — and simplification necessarily means leaving out details; that's not a flaw to be fixed but the entire point, since a model with zero simplification (a 1:1 map) would be exactly as unwieldy and useless as the raw, unprocessed reality it was meant to help you navigate.
Read more about the topic
How to Use Occam's Razor Without Getting Cut
"Among competing explanations that fit the evidence equally well, the one that requires the fewest assumptions should be preferred — but Occam's Razor is a tool for narrowing initial hypotheses, not a substitute for evidence, and misapplying it (assuming 'simple' always beats 'accurate') can mislead badly."