There is a reason editors exist, and I think that reason is simply the need to slap writers' hands and stop them from editing where no editing is needed. 

So I'm proofreading The Badlings, right? And this thing has already been through 5 drafts and 2 editing scrubs and is supposed to be final, then I catch this clumsy description that is very important. It shows a major world change, yet I glossed over it. Here it is (WARNING!!! Spoilers.):

"A faint ahhh went up from them, and for an instant they forgot themselves, lost in the sight.
Both the steppe with the distant windmills and the sky with the shining sun were now perpendicular to the dirt wall. Behind Mad Tome’s ugly grimace that hung in the air like an unwelcome apparition the sky simply ended, as if it was nothing more than a flat mirage, and beyond it stood another page. It was dark, shrouded in the night. Its bottom curled up slightly, and beyond that the next page was visible, green and lush. A forest? A roiling ocean? It was too far to tell.
The boys looked straight up and saw the pages connect. They were bound to Mad Tome’s spine, hanging from it like curtains.
'We could’ve just walked the other way and simply stepped over onto Dracula’s page,' muttered Grand.
They stared at each other, speechless. "

What do I do? Instead of actually proofreading this as I'm supposed to, I start editing and spend a whole hour on on fixing this one stinking paragraph, and this is what comes out:

"A faint ahhh went up from them, and for an instant they forgot themselves, lost in the sight.
The steppe was now the wall, the dirt wall was now the ground, and behind Mad Tome’s grimace that hung in the air like an unwelcome apparition rose yet another wall: another page. It was dark, shrouded in the night. Its bottom curled up slightly, and beyond that the next page was visible, green and lush. A meadow? A forest? It was too far to tell. But most surprising was the space above their heads. Both pages ran up into shadows where they connected, forming a pointed vault—Mad Tome’s spine.
'It’s like we’re under an open book,' said Peacock.
'Like if you opened it and put it down like a tent!' added Rusty.
'Um, if that’s how it works, then we can just walk out of here,' said Grand thoughtfully. 'I mean, if we walk long enough, at some point the pages will end, and we’ll find the cover and go under it and maybe get back out at our duck pond.'
They stared at each other, speechless. "

Then I get very tired, because its already evening. I decide to proofread another 10 pages and call it a day, feeling rather accomplished with myself.

This morning I wake up and still that paragraph is nagging at me. So I go back, reread the original version and see that I started second-guessing myself. I asked Royce to confirm it, read both bit aloud, and he said, "Why did you kill it? It was good. The second one starts telling, not showing." I said, "Yeah, you're right." So I get to massaging it for 1 hour this morning, then finally revert back to the original and add a bit of the new one, so in a way I combine the two:

"A faint ahhh went up from them, and for an instant they forgot themselves, lost in the sight.
Both the steppe with the distant windmills and the sky with the blinding sun were now on their left, perpendicular to the dirt wall. Mad Tome’s grimace hung directly above them like an unwelcome apparition. And to their right rose another page, dark, shrouded in the night. Its bottom curled up slightly, and beyond that the next page was visible, green and lush. A meadow? A forest? It was too far to tell.
The boys looked straight up and saw the pages connect. They were bound to Mad Tome’s spine, hanging from it like curtains.
'It’s like we’re under a book,” said Peacock.
'Like if you opened it and put it down like a tent!' added Rusty.
'Um, if that’s how it works, then we can just walk out of here,' said Grand thoughtfully. 'I mean, if we walk long enough, at some point the pages will end, and we’ll find the cover and go under it and maybe get back out at our duck pond.'
They stared at each other, speechless."

You see? Instead of making it better I'm starting to make it worse. This is how I know the book is done with me and I'm done with the book. After I'm done proofreading the remaining 100 pages, I'M NOT TOUCHING THIS BEAST ANYMORE. INTO THE PUBLISHING LAND IT GOES.

Besides, I have a gazillion unfinished things to do that I keep pushing back, like the blog post about pricing your books, and finishing the publishing of Blue Sparrow 2 everywhere and sending a newsletter about it, and washing my socks, and sleeping (my body has barely given me 5 hours of sleep every night over the last week), and so on.

How can you tell if you're starting to over-edit? You can't. But you will sense it with experience. Siren Suicides should've been edited more, and Rosehead could use another round of editing. Irkadura was edited just perfectly, and with The Badlings I went overboard. So now TUBE will end up perfect, unless, of course, I learn something new while I write it. Which I will. Until then...

ONWARD.

P.S.: I have 94 pages left to proofread as I'm typing this, and then Royce will do one quick read after that to see if I missed anything, and then to formatting The Badlings goes. If you hear me tell you I touched it again, you're allowed to spank me.