Writing vs Programming

Tom Kyte's blog referred to this, and it is something I've been realizing myself lately. I recently changed from doing programming and DBA work to developing curriculum about DBA work. And, I've noticed that with the latter, schedules are more strict. I'm theorizing the reason to be the fact that with coding, you know when you're done; you're done when it does what it's supposed to do. So, having a schedule is a help, and a goal, but when the due date comes, if it's not ready, you keep working on it. With writing, there is less of an inherent definition of "done". So, when the due date comes, you're done (within reason).