Along with being an author, I'm a freelancer as my day job. That means most weeks, I'm editing or proofreading someone else's story. Sometimes five stories. (Yes, in one week. First, lengths differ; and second, I work in different stages of editing.)
Some clients are more draining to edit than others. A client being "draining" doesn't mean they're particularly bad—it just means their edits are more thought-intensive. For example, if you tend to use wrong words (which is actually a common issue, I suspect connected to the auditory learning style), I'll have to either puzzle out or mark with a comment every instance of that wrong word usage. That requires a different sort of brainpower than just correcting some punctuation mark issues.
That does not mean the prone-to-the-wrong-punctuation-mark author is any better or worse than the prone-to-the-wrong-word author. It's just different. And the amount of time involved in fixing either of them primarily depends on how frequent the problem is in their manuscript.
But again—even a writer who has frequent issues in word choice or grammar (or any other writing problem) isn't necessarily a "bad" writer. Fiction writing is storytelling. A writer who can up with an enjoyable story is a good writer. (Using "good" in the colloquial sense, not in the Biblical sense, here.)
The writer might just need to work on the delivery for the story to be conveyed to others. But grammar and technique can be learned, if an author is willing. It might take a while—it might take several stories—but it's learnable.
How to come up with a story? Far harder to learn.
What does this have to do with zombie brain and needing a break?
When I'm working on a story with a particular problem, I have a much harder time reading things with that problem.
When I've been working on more draining things—and what drains an editor will depend on the editor—I hit a point wherein I don't want to do anything related to the day job. (I suspect this is what Kris Rusch is referring to when she says editing for The Magazine of Fantasy and Science Fiction was terrible for her writing career.) I can usually still write, at least a little, though when the zombie brain gets really bad, much of what I write comes out wrong and needs redrafting.
That isn't to say I need a week off from the day job. (Which happens, sometimes, but I try to schedule frequent enough breaks to avoid needing that.) I just need my off hours to be off.
Which wreaks havoc with everything from my own writing work to my reading plans to my beta'ing for other people. Add in that I've had accidental allergen exposure multiple times, lately… and I'm left aplogizing to those people to whom I offered to give feedback but I haven't yet done so. (When I'm not drained from the day job, I'm drained from the allergies. I hate strawberry season.)
So here's my public apology. Current plan is to get all those done next week, Lord willing.
What do I do when I have zombie brain to the point that I have trouble even reading?
I play computer games, which relax me, or I make some homemade…thing. (It's about as likely to be something like hair conditioner as it is to be something edible. There is a reason my mother and I keep labels in the kitchen…) I also sometimes play with Gimp and book covers, or I write a macro or code snippet.
What about you? What do you do when zombie brain hits? Care to share anything you find particularly draining?