The "S" has long been one of memedoms greatest mysteries. Six straight lines connected by a series of diagnal ones form a shape that is synonymous with the notebooks and Trapper Keepers of students around the world. But while this symbol has become a staple of schoolyards everywhere, no one seems quite sure where it came from.

Most commonly referred to as the Stüssy S, referring to the supposed logo of the clothing company "Stüssy," many have pointed to anecdotal evidence that teens and tweens have drawn it long before the company launched. So if Stüssy didn't popularize the S, where did it come from?

After years of deep dives into the subject, YouTuber LEMMiNO comes closer than just about anyone to a definitive origin for the symbol. Digging into articles, books about graphic design and geometry and thousands upon thousands of message board posts, LEMMiNO finds examples of the "S" throughout the last century and from around the world. in fact, the video shows examples from every continent except for Antarctica. Overall, they decide that it's best to just narrow down examples to time periods rather than specific creators. What they find are examples of the S in the 70s horror film Piranna, the work of American artist Jean-Michel Basquiat, graffiti designs dating back to the 1960s and, finally, a geometry book from the 1890s.

While it had long been suspected that the S comes from graffiti because of the straight lines and hard edges, which would provide street artists with more control, the 1890 book Mechanical Graphics by Frederick Newton Willson, a professor at Princeton University, includes a very similar looking "S." In its examples of "Railroad Type," a font described in the book, Willson draws an "S" with the straight lines associated with the common "S." Furthermore, LEMMiNO theorizes that it's possible that Willson taught students to draw the "S" while teaching at Princeton, which would account for its spread.

LEMMiNO's work is an invaluable summation in the history of S, one of the world's most popular and recognizable pre-internet memes. From its rise to its many misconceptions to dead ends and a possible conclusion, the video could put us on a path to finally solving this long-running meme mystery.