I've seen it mentioned a few times lately that various writers are being granted permission to suck. It came up at the latest writers' group meeting, it came up on a podcast of Writing Excuses I listened to, and it's apparently the subject of this week's NaNoWriMo pep talk. (Yes, I should've been including links in my posts from the beginning. Didn't even occur to me until tonight's post. Sorry.)
During NaNoWriMo, people are granted permission to bang out the worst prose of their lives. They need to get to 50,000 words in a month one way or another, and no one said those words have to be good. Therefore, if one is to get beyond their second-guessing every word as it pours forth on the page, feeling like one is allowed to be terrible at it is a good way of powering past that. It's the major trick behind free-writing, which I've espoused before. When you're typing away with no attention paid to whether the words are any good or if they make any sense strung together, you are getting words down, and you get to liking that feeling so much that you want to keep doing it.
But there's another reason, other than simply getting the words out so the work is written. The reason is the gap, as explained by Ira Glass in the link. As you're writing, simply because you haven't been doing it long enough, you will notice your mistakes. You have to keep writing and practicing and getting better, or your writing will never match your expectations. Even when you've gained experience and leveled up as a writer, as I've heard many a writer I admire say, you're still not so perfect that you won't require editing. As soon as it goes onto the page, it has sullied the perfect image you held in your mind of the flowing, smooth, beautiful story you wanted to tell.
You cannot fix your manuscript if you don't see the mistakes. And, even if you don't see them, they're there. I don't know of a single writer (feel free to correct me) who can churn out publishable, unedited, perfect first drafts. Most writers I know of, especially my favorites, require extensive editing of their first-draft novels, and openly talk about that editing process.
My biggest problems with critique have come when I was too enamored of the words on the page, too convinced that these words were the only correct way to tell the story. The greater the distance between myself and my words, the less I cringe when people tell me where they see the source of the problem.
And so, I give myself permission to suck. If I can't figure out just the right way to describe something, just the right scene transition, just the right piece of witty repartee, I write what comes to mind, knowing I can always go back and edit in my inspiring bit of prose. If I'm on a roll, but I can't remember if I've dropped in some foreshadowing yet, I write it, anyway, and check in my read-through if it's too heavy-handed. If I realize that an earlier bit I wrote contradicts something I'm typing, I make a note to myself and keep going forward.
I would venture to say that good writers aren't the ones who can get it right the first time. Good writers, in my opinion, are the ones who can polish their manuscripts into well-told tales from bad writing.