This implies technology that could read minds. We're not even close.

I contemplated this idea a while back. I concluded that the closest we could come with current technology (possibly) would be a drug that would enable you to stay more completely aware while you are asleep and dreaming. A lucid dream drug. If you are aware that you are dreaming, then you can learn to manipulate your dreams. This could be a lot of fun. Unfortunately, it might be too fun as people might become addicts. There also would likely be health issues.

I have experienced this several times and although it can be amusing, hidden fears can surface and make a real terrifying experience.

Yes, the trick is to delve into and understand them when they present themselves. Which, in turn, more often than not in my case has either "clicked" resolving the scary thoughts or, made me laugh uncontrollably at it's origin...errm... yeh...

The dream device, i'm sorry, is very unoriginal, but I suppose it must warrant inclusion in WhyNot.

I would definitely like this - shouldn't be too hard.

Here's something to try. Keep a pad & pencil by your bed. When you wake up in the middle of the night write down what your dream was.

Seriously. . .

Read them the next morning. Sometimes you won't even remember writing it down, much less what it was about. And sometimes the writing will be totally unreadable.

Do this for a few months and see what patterns develop. You will be amazed at some of the stuff you didn't know you thought about.