I think the state of dreaming, a dissociative mindset, sleepiness, and to some extent, meditation, certain drugs: these all can lead to creative and insightful

I think the state of dreaming, a dissociative mindset, sleepiness, and to some extent, meditation, certain drugs: these all can lead to creative and insightful thoughts. Edison used to take frequent naps, which may have been a font for his many ideas.