An important aspect of our awake world is that we do not perceive it simply because it independently “exists out there,” much like we do not perceive a dream merely because it exists. A notion (pratyaya) first arises in the intellect, and we then project it outward to appear as an external object. This mechanism is common to both dream and waking states. Through constant repetition and habitual engagement day after day, we gradually become convinced that the objects perceived by us are independently real and constitute an objective world.
Consider this: when the mind ceases to imagine waking-world objects and becomes occupied with dream objects, the waking world disappears from experience. When neither the waking nor the dream world is conceived, no object is perceived at all; this is the condition of deep sleep (suSupti).