Writing and Editing

I find that editing can be a bit frustrating if the writer hasn't made the changes that were requested to make the manuscript flow better.
I don't enjoy making the same comments, notations, etc., on each subsequent draft as it is a tad bit burdensome. I think that sometimes the writer may have made some changes, but forgot to hit the save key, or perhaps overlooked the aforementioned changes.
I want to see my writers improve and not backslide. It's important for a fledgling writer to improve on his/her skills so that the editor, (me) will continue to work on full length manuscripts with this person. Otherwise, I may say, I am too busy for this work.........
I like to see improvements and when it doesn't happen, it's rather annoying. It kind of reminds me of the times I've taught English Composition to college students where the student would ignore a specific change thinking that I had so many students that I would overlook the glaring error.
For me it's kind of tough to do that since I have a photographic memory for most things, and can remember an error that someone made a couple years ago. It would amaze me that a young adult would believe I wouldn't notice it. At any rate, students learned pretty quick that I wouldn't let those errors slide, and they had to be corrected to make the paper better.
Editing is a tough job...................