I wished this was "Outline of outlines of outlines". I used to seek out those articles a lot in my free time when I was a student. It only made my hunger of knowledge grow.

    https://en.wikipedia.org/wiki/Outline_of_computer_programming
    https://en.wikipedia.org/wiki/Outline_of_computer_science
    https://en.wikipedia.org/wiki/Outline_of_mathematics
    https://en.wikipedia.org/wiki/Outline_of_history
    https://en.wikipedia.org/wiki/Outline_of_linguistics
    https://en.wikipedia.org/wiki/Outline_of_law
    https://en.wikipedia.org/wiki/Outline_of_biology
    https://en.wikipedia.org/wiki/Outline_of_science

etc.