I didn't see this thread before. Thanks, Ed T.

I agree with Jeri when she said: "Maybe it's just me, but daydreaming and brain inactivity seem mutually exclusive! Creativity and those rich details in essays come from imagination, and imagination is what daydreaming's all about."

Daydreaming? I think productive daydreaming is a demanding activity. How about people who make a career out of formulating a story? Authors are not notably prone to Alzheimers, so far as I know.