The Husbinator says this is become I'm special in the teasing kind of way. I do weird things a lot, there is no denying that, but these head-scratching writing moments are a common problem for a lot of us.
If you've read something a thousand times already, you're no longer looking at it with a fresh set of eyes, or a fresh perspective. Your mind is cluttered with the way it should be written, your take on what it should say, or a million other little things that can be the difference between a great sentence (or paragraph or scene), and one that throws your readers for a loop. The same rings true for if you've just written it. What you intended to say can get lost beneath heavy prose, disjointed thoughts, rambling, and a million other little things we don't necessarily notice as we write.
And this is where editing can be crucial.
Anyone who writes can probably attest to how often they've been told (or told someone) to "forget about it". This doesn't mean hide your story in some dark corner and never take it out again. It's not a criticism at all, or not usually, anyway. It's a sound piece of advice that has saved more than one writer.
So, forget it!
Put down whatever you're working on for a while before picking it up again to edit. This lends a certain perspective we're lacking "in the moment". When we wrote that sentence two weeks ago, we might have known exactly what we meant, but when we pick it up again, we're able to look at it critically and decide whether a reader who has never seen it before is going to get it, or if we've lost them somewhere along the way. We can also better judge if that bit of background is truly important or if it's info dump.
We might need to know every little detail about John's life, but readers usually don't. If you're bored editing it, chances are your readers are going to be bored reading it. Likewise, if you don't know what point you were trying to make, your reader probably isn't going to get it either.
That's pretty dang important info!
The last thing a writer wants is to force a reader to spend ten minutes trying to decipher a sentence, or to leave them wondering what the heck you were thinking. Better a head-scratching session in private, than one with a submissions editor, a reader, or a critic. And if you're like me, you're going to find a lot of instances where what you thought you said isn't anywhere close to what you actually said.
Not enough to make you "forget it"?
Putting aside writing before jumping into editing is also a great way to catch those little errors that we often overlook. Skipped a word? Used an incorrect spelling? Missed a comma? Added an extra word? Chances are you're going to read right over those little mistakes while writing, but once you've set it aside for a while, those fresh eyes are going to catch those mistakes right away.
No editor (that I know of) expects perfection from start to finish, but no editor wants to see a finished manuscript that reads more like a first draft either. Catching those little mistakes can be as critical as deciding how much info is too much, or whether or not John's story really does continue for 100 pages beyond the big finish.
You want your novel to have the best chance possible when you send it out into the world, so forget it now, and you won't regret it later. And don't worry, I'll be scratching my head right alongside you!