Sometimes scientists and mathematicians solve problems in their dreams. I can even remember two occasions when I solved programming problems in dreams.
But that was a long time ago (decades, literally). I've recently been having XAML dreams and they can be quite unpleasant. I'm not sure why. Maybe its all those pointy angle brackets.
I never really understood the true power of dreaming, however, until I read this article on a web site that certainly isn't part of my routine reading. It's one of those things where you don't know whether to laugh or cry.