Interesting article on the science behind why our mind wanders. I think we can all be blamed for a bit of off-topic thought adventures. But some of the worst day dreamers may have a good excuse. Apparently a wondering mind is a creative window of opportunity. According to the linked article, we spend 46.9% of our time daydreaming, usually because we are bored, disinterested, or have nothing stimulating to think about.
This seems true. Remember the four B's of inspiration? Bed, Bath, Bar & Bog - the 4 most likely places you'll come up with an idea, probably because your not focused on anything in particular, drifting between consciousnesses.
What does this have to do with lessons? How do we discourage boredom in class? Keep students stimulated, even the ones with little interest in the subject?
Or do we encourage a bit of day dreaming? While still keeping that bit of meta-awareness to be able to capture any bright ideas that come out of it...