In a world where GPS is a thumb stroke away, most people take maps for granted. It’s hard to fathom that the oldest surviving maps had little to do with reality. The Babylonian Map of the World, for example, was a clay tablet about the size of a first-generation iPhone. Created between 700 and 500 BC, the map shows Babylon in the middle, with the Euphrates River cutting through the center and the ocean on all sides. As Smithsonian Magazine explains, it wasn’t a map for navigation — more of a way for the map-holder to understand the idea of the world around them. Accuracy was an afterthought.

It would be centuries before an astronomer and astrologer named Claudius Ptolemy attempted the first realistic map — a two-dimensional depiction of what Ptolemy understood to be a spherical Earth. This is a prime example of when a great thinker applies a new mental model — essentially, a new way of thinking about things; a heuristic for interpreting the world. Rather than accepting earlier, more symbolic pictures of the Earth, Ptolemy ventured to create a true-to-life representation. He shifted the way of thinking from storytelling to describing reality.

Mental models help us to understand things more fully and come up with smarter, more innovative solutions. But as Charlie Munger, former vice chairman of Berkshire Hathaway, Inc., used to say, you have to build a “latticework” of mental models, employing various models to maximize your understanding of different situations.