Megan McArdle wonders if procrastination stems largely from a fear of failure:

Over the years, I developed a theory about why writers are such procrastinators: We were too good in English class. This sounds crazy, but hear me out.

Most writers were the kids who easily, almost automatically, got A’s in English class. [...] At an early age, when grammar school teachers were struggling to inculcate the lesson that effort was the main key to success in school, these future scribblers gave the obvious lie to this assertion. Where others read haltingly, they were plowing two grades ahead in the reading workbooks. These are the kids who turned in a completed YA novel for their fifth-grade project. It isn’t that they never failed, but at a very early age, they didn’t have to fail much; their natural talents kept them at the head of the class.

I’ve seen this in myself and my daughter: when something is comparatively easy, it’s bewildering when it gets difficult.

With age, we begin to realize that everything we write isn’t perfect. Most of it isn’t even good. Procrastination becomes self-defense. The scene you haven’t written yet can’t be terrible.