Yeah, essays for me don't really follow the old PEE and rule of three structure but they're still useful. Another example of what you explained with biology is chemistry. You get introduced to atoms, then atoms being made up of protons/neutrons/electrons and then you learn about ions and electron 'shells' which are explained to you by saying that certain electrons orbit the nucleus at a 'further' distance. (this is about where my education in chem stopped) Then you learn that it's not actually about distance or energy levels or something like that? Every level of complexity tells you something useful but there's usually another one just beyond it.

I did a course in my first year of Computer Science which was a combined cognitive science and writing course. The idea was that we would learn about cognitive science and then write essays on it (three 1000 word essays), but also that we would learn how the act of writing is in fact very similar to other creative activities such as programming or invention. I wonder if there is a difference in how different sorts of programmers write. Java programming and Haskell programming are very different experiences, maybe the different habits you pick up bleed over into other areas.