Megan McArdle in The Atlantic:
I once asked a talented and fairly famous colleague how he managed to regularly produce such highly regarded 8,000 word features. “Well,” he said, “first, I put it off for two or three weeks. Then I sit down to write. That’s when I get up and go clean the garage. After that, I go upstairs, and then I come back downstairs and complain to my wife for a couple of hours. Finally, but only after a couple more days have passed and I’m really freaking out about missing my deadline, I ultimately sit down and write.”
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. (There are exceptions, but they often also seem to be exceptions to the general writerly habit of putting off writing as long as possible.) 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.
More here.