I actually think it has less to do with "Oh yeah, that’s probably better, because I’m sure I wrote that sloppily, too fast and haphazardly, using images or vocabulary far too "in" for people who aren’t me to get", than as writers (don't forget I'm also one), we tend to know our own stories SOOO well that we don't see the areas where readers might need more info (because that "more" is already there in our heads). Which is why even though I am a writer/editor myself, I always work with an outside editor when the time comes. ;)