I believe (I know—but can't prove!) that scientists will soon understand the physiological basis of the "cognitive spectrum," from the bright violet of tightly-focused analytic thought all the way down to the long, slow red of low-focus sleep thought—also known as "dreaming." Once they understand the spectrum, they'll know how to treat insomnia, will understand analogy-discovery (and therefore creativity), and the role of emotion in thought—and will understand that thought takes place not only when you solve a math problem but when you look out the window and let your mind wander. Computer scientists will finally understand the missing mystery ingredient that made all their efforts to simulate human thought such naive, static failures, and turned this once-thriving research field into a ghost town. (Their failures were "static" insofar as people think in different ways at different times—your energetic, wide-awake mind works very differently from your tired, soon-to-be-sleeping mind; but artificial intelligence programs always "thought" in the same way all the time.)
And scientists will understand why we can't force ourselves to fall asleep orto "be creative"—and how those two facts are related. They'll understand why so many people report being most creative while driving, shaving or doing some other activity that keeps the mind's foreground occupied and lets it approach open problems in a "low focus" way. In short, they'll understand the mind as an integrated dynamic process that changes over a day and a lifetime, but is characterized always by one continuous spectrum.
Here's what we know about the cognitive spectrum: every human being traces out some version of the spectrum every day. You're most capable of analysis when you are most awake. As you grow less wide-awake, your thinking grows more concrete. As you start to fall asleep, you begin to free associate. (Cognitive psychologists have known for years that you begin to dream before you fall asleep.) We know also that to grow up intellectually means to trace out the cognitive spectrum in reverse: infants and children think concretely; as they grow up, they're increasingly capable of analysis. (Not incidentally, newborns spend nearly all their time asleep.)
Here's what we suspect about the cognitive spectrum: as you move down-spectrum, as your thinking grows less analytic and more concrete and finally bottoms on the wholly non-logical, highly concrete type of thought we call dreaming, emotions function increasingly as the "glue" of thought. I can't prove (but I believe) that "emotion coding" explains the problem of analogy. Scientists and philosophers have knocked their head against this particular brick wall for years: how can people say "a brick wall and a hard problem seem wholly different yet I can draw an analogy between them?" If we knew that, we'd understand the essence of creativity. The answer is: we are able to draw an analogy between two seemingly unlike things because the twoare associated in our minds with the same emotion. And that emotion acts as a connecting bridge between them. Each memory comes with a characteristic emotion; similar emotions allow us to connect two otherwise-unlike memories. An emotion (NB!) isn't the crude, simple thing we make it out to be in speaking or writing—"happy," "sad," etc.; an emotion can be the delicate, complex, nuanced, inexpressible feeling you get on the first warm day in spring.
And here's what we don't know: what's the physiological mechanism of the cognitive spectrum? What's the genetic basis? Within a generation, we'll have the answers.