Different parts of your brain work at different speeds.  If you use the first idea that pops into your head, you just get the benefit of the fastest module.  Sometimes people do that and later think of a better idea.  That’s because the slower modules can do a more thorough job.  So thinkerers like to sleep on a problem before they finish it.

                                                  Thinkering is like barbecuing. 
Faster is not better.

Sleep learning gets to be a popular psychological fad every so often.  Sounds like a great idea.  You spend one-third of your time sleeping, so why not use it for learning?  A while back, you could buy speaker pillows and audio-tape machines with timers to start the tape after you got to sleep.  People tried that and got smart.  Smart enough to see that it didn't do what they needed.

On the other hand, lots of people want to sleep on a problem before they make a decision.  Lots of people wake up in the middle of the night with a good idea, with the solution to a problem, or with a word they were trying to remember the day before.  You can probably remember a time when that happened to you.  If not, maybe you’ll remember it tonight.

Psychologists call this incubation.  You really don’t need to go to sleep for it to work.  You just have to do something different.  The great thing about incubation is that you already know how to do it.  So we're not going to try to sell you a flashy book called:

Solve Problems While You Sleep!!!

Instead, we’ll just mention what you need to know.  Parts of your brain can work on problems without your attention, even when you are asleep.  Sometimes those modules will find solutions more creative than the ones you will find by consciously worrying about the problem.

Incubation is too good to leave to the chickens.

To keep those modules from helping with the problem, just pick the first solution that comes to mind.

To get those modules to help, work on the problem until you begin to feel frustrated.  Then set the problem aside for a day or so.

Trust your brain.  Treat incubation as a routine part of figuring out what to do.   It is not just something you have to do because you can’t think of anything better.

 Trust the Force, Luke.