I have a lot of incomplete projects dating back more than two decades. I also have many completed projects I never seriously tried to publish or distribute. In other words, I do a lot of writing, sketching, programming, and planning without following through to the expected conclusion.
What's strange is that I do complete, with a lot of anxiety from a perfectionist streak, school work, magazine columns, grant applications, handouts for my students, and projects assigned by other employers. So, it isn't everything I don't complete... just the projects I seem to really want to complete for myself. My perfectionism is limited (somewhat) by deadlines, but when there is no deadline, I never stop reworking a project.
Perfectionism is unhealthy.
I outlined a series of science fiction stories in the fifth grade. I have all the notes from fifth grade through the present. I start writing the stories, get depressed with the results, and restart. I'm not a science fiction / fantasy reader because I find flaws in the stories. I want to write something that is impossible to write, of course. Novels, regardless of genre, contain minor errors, but anything scientific is going to be especially challenging to perfect. I should just write, be done with one of the novels, and move ahead.
I've done no better with my start-stop-start over crime novels or thrillers. I complete something... then decide it should be rewritten. More often, I reach the half-way mark and start again, as if 60,000 words or more should be tossed aside.
Now, I do complete some stories. In fact, I've completed a lot of short stories, theatrical scripts, and lots of poetry. But, I don't do anything with those works, either, because I wonder how good they really are. Self-doubts eventually win and I do nothing with the works.
I've tried weekly deadlines for myself, writers groups, and having a student edit my works. Nothing seems to counter the pattern of starting over too often. I'm hoping this changes someday.
It's sad that I can be amazingly productive and end up canceling out my efforts with panic.