It's liberating and exciting when you learn there are tons of established structural patterns more interesting than five paragraph and you're expected to use and modify them.
Then you have to relearn the five paragraph essay for the GRE, and it's worse than the first time.
The mandatory writing courses at top schools generally have some structures that are forced adversarially on first year students, like the "lens" essay. They're not bad but the students have to shoehorn whatever they're writing into the specified format, regardless of what the writing ends up needing to be.
One of the best ways to really 'get it' is to make outlines of things that are already written, to learn how it flows from one topic to another and back, and if it actually works. You can also reverse outline things you've already written and get a good idea of what's happening or missing and how it could change.
Then you have to relearn the five paragraph essay for the GRE, and it's worse than the first time.