“Naps are essential to my process. Not dreams, but that state adjacent to sleep, the mind on waking.”
—William Gibson
Yes, there are days when nothing works, our head is overloaded, we think of a thousand directions and whatever we do, we feel tired. Everyone has these days. Then—at least for me—there's only one solution: take a nap. Sleep tidies up the brain, it actually does the most demanding work for you. And when you wake up, your thoughts are sorted and you can function normally.
Naps are a full-fledged creative tool for many artists and entrepreneurs. Many (and often the best) of their ideas have come to them in their dreams. Elias Howe—the inventor of the modern seeding machine—became famous thanks to his invention, but especially thanks to the groundbreaking innovation of putting the eye of the needle at the point. This idea came to him during his wild dream.
In his book The Art of Creative Thinking, Rod Judkins describes it like this:
“In his first attempts he put the eye of the needle at the conventional end, but it didn’t work. Then one night he had a dream in which he was ordered to build a sewing machine by a cruel king in a strange country. The king gave him twenty-four hours or he’d be executed. He struggled with the needle’s eye, but just as in real life, he couldn’t make it work. He was taken out to be executed and noticed that the soldiers had spears that were pierced near the point. The solution presented itself. The inventor begged for more time. At that point he woke up. It was four in the morning. He jumped out of bed, ran to his workshop and created a needle with an eye at the point.”
Salvador Dalí—other master of naps—used this dreamlike state for the creation of his surreal paintings and also movies with Luis Buñuel. Richard Wagner's Das Rheingold or Lewis Carroll’s Alice’s Adventures in Wonderland—same story.

The creative ideas that you're looking for and sometimes don't come to you often float beneath the surface of your mind—the deeper you dive, the more you can discover. Naps may seem unproductive and unpredictable at first, but they often lead to completely new ideas and, if nothing else, at least to clearing the mind. Don't force it. Sometimes the best and most creative way can be simply to take a short nap.
“The world needs dreamers and the world needs doers. But above all, the world needs dreamers who do.”
—Sarah Ban Breathnach