That's how I operate, too. I have a whole folder of ideas and outlines and first chapters of stories that may never see the light of day... or maybe they will, eventually, when I'm done with some of my other projects.
I totally get wanting to post things right away because I'm excited about them and want the feedback, but a little self-control goes a long way. I feel bad because I started two new stories this past summer, one of which was one of those ideas that I'd been sitting on for YEARS before finally getting started on it, and the other was the result of a rush of inspiration that I couldn't get rid of. I sort of abandoned one for the other, but not until I'd spent like a week planning and churning out six chapters of the new story to make sure I was really going to stick with it. I'll go back to the other one once it's finished, and I hopefully won't post any new stories until both of them are.
I really prefer to be a one-story-at-a-time kind of writer and finish one project before I start another. With the ongoing collaborations I'm involved with, I let myself have those as back-up stories, but I've been unusually overwhelmed this past year with too many stories in progress at once. I really want to finish most of them before I start, or at least post, anything new. I don't want to be one of "those writers" you guys mentioned who starts story after story and never finishes anything, 'cause that's not fair to the readers.