One time in high-school English class I wrote a pair of essays. One was the other exactly reversed, using sentences as the unit. The thesis statement of one was the introductary sentence for the "conclusion" paragraph in the other. It was challanging to make each paragraph topic sentence reverse with the concluding sentence.
My friend turned in one, I the other. I got a whole letter grade higher than he did, even though (as it turns out) his was the "original" and mine the reverse. I think the teacher noticed one particularly quotable sentence was duplicated, but not that all of them were.