In the late 90s? Surely OOP, code re-use through encapsulation and inheritance, the relational model (though on the way out), and making XML of all the things should have been some of the "interesting topics" at this time.
The best way to understand how an operating system works is to build a simple one yourself. But you can't build one before you have learned how to program.
I believe it's a bit similar case with many other topics nowadays. Having some basic Python skills unlocks opportunities in other fields, such as machine learning or robotics.
I was a grad student in the late 80s and early 90s, and I remember having classes that took this approach. It took me years to recover and repair the damage. Understanding how a real OS works is not actually that hard. It's actually easier if you start with that than what I went through, which was a bunch of abstract academic bullshit that left me with no idea how it was supposed to make contact with reality.