Many of the various cultures of the Pacific found their way to their present home using devices like the one shown above to memorize information about their environments and common travel routes. It was not a standardized practice- most people could not read a chart made by another, and a family’s navigational knowledge was often considered a family secret (source).
A key part of this navigational system was the star compass. Much of the inhabited Pacific islands are very close to the equator, which means stars appear to rise straight up into the night sky and to set straight down (unlike the sharply angled path they take in, say, Alaska). Navigators used this knowledge to build a mental star compass, memorizing which constellations rose at which points of the compass, and the order in which they rose (since once overhead, it can be tricky to follow). (source)
The other important component in their navigation was the regular and predictable way that waves interacted with islands in the Pacific. Certain kinds of swells regularly indicated the presence of an island in a certain direction, which navigators used both to find their way to known islands and to observe the presence of a previously unknown island- all the while slowly building their family’s knowledge of the world and taking notes in the form of those beautiful, complicated stick charts.
Being the nerds we are, complicated secret knowledge is right up our alley! There is a great deal to inspire, here; first of all, it evokes Western concepts of magic. However, the various pacific islanders have a concept of magic that is less about highly ritualized secret societies and more like what the recent Alice in Wonderland movie called “muchness.” (Though this, of course, varies. Also, fun fact: one of the words for this quality is mana. Yep. Just like in all your video games!) Much of magic in video games has been highly influenced by the Japanese interpretation of mana, so much so that even Western games adopt the mana mechanic even when set in Western-type magical settings.
The second bit of inspiration is the use of things besides written language as a method of storing information and aiding the memory. Little props can do a great deal to add to the feeling of a fictional culture or profession. For example, a caster-class that relies on secretive rituals might use grimoires to record their private knowledge- or they might constantly be making little knick-knacks out of wood and reeds that appear meaningless to outsiders but represent the passed-down knowledge of hundreds of years of magical experimentation.
If you are a city slicker and you don’t have any bits of wood and reeds around to use, you can always use diffuser reeds and floral tape for a similar effect.