I am a high school student, and I have been thinking about the way knowledge is structured. In schools and universities, we study subjects such as mathematics, physics, biology, and many others. This has led me to wonder: exactly how many subjects exist in total? It is generally understood that all the knowledge humanity currently possesses is finite and organized into distinct areas. I am interested in knowing whether there exists a comprehensive list, table, map, or conceptual framework that captures the entire body of known human knowledge without excluding anything. In other words, I am seeking a complete and exhaustive classification of all subjects, such that no area of knowledge is left unaccounted for. I wish to ensure that I am not unaware of any subject.
If you skim the high-level book categories at https://en.wikipedia.org/wiki/List_of_Dewey_Decimal_classes, you may conclude this is is beyond a lifetime's work.
You may want to trace the history of librarianship.
(Classification systems are very much an information science topic... and they're pretty damn important. Along those same lines - you'll want to think carefully and critically about what is seen as canonical knowledge, and what's "in" those fields, versus what is perceived as "utter crackpot bullshit" that nobody takes seriously. The fields you've mentioned ALL have a significant amount of bleed at the edges - where does math become mathematical physics and then 'really physics' ... it's just not that easy.)
Fanboy comment: just google Eugene Garfield. Have fun!