REM

It is still a mystery why we dream and why dreams appear to have a symbolic form. There are some theories but...

How do you know you're not dreaming right now? Are you sure? Can you prove it? How often were you sure it was real and that you were not dreaming, but you woke up shortly after?

What if your entire experience, which you think is your life, is just another dream, a dream that you can't wake up from.