Everybody has the experience of dreaming, and some of us may have the experience of being aware of dreaming in a dream. Nevertheless you are not able to wake up from a dream; the awareness of dreaming can somehow release the clinging to the realm of a dream.
Buddha often used ”dreams” to describe the worldly life and existence. You can’t say a dream does not exist, but it is not real! We should not deny the worldly life and existence, but they have an illusive nature!
How to perceive and understand this illusive nature as a “dream”? Buddha provided us with some other metaphors, such as bubble, dew and lightning. If you have time, please find a chance to observe them. What are their common characteristics? Yes, they manifest the impermanence more obviously, from inside to outside, the form depends on other conditions except itself. Through our eyesight, we believe that there is a bubble, there is dew, there is lightning, indeed there is, but none of them ever has an inherent independent self.
This illusion was caused by accumulated habitual mindless - “it seems everything that exists depends on itself”, and sealed in deep mind since very no-beginning. “Sealed” means that an illusive concept has been merged subtly with your view and thought, so that even though sometimes you can work out the “dependent arising” through analysis, it is not yet strong enough to detach that illusive “magnetic field”.
So, we need to be mindful of constant awareness and continuous rational thinking, in order to keep awareness of “dreaming”, until one day we wholly awake!