The very term reality implies that experience has been divided into what is considered real and what is not real. After all, if absolutely all experience is defined as reality, so that the term becomes synonymous with "what is" on every level including that of imagination, then the term "reality" loses its meaning as there is nothing to contrast it against. So reality is the name we give to that part of our experience which we conceptualize to be "real" in contrast to that part of our experience we consider to be "unreal".
The position of the dividing line between what is real and unreal — our definition of reality — depends on what we personally define as real. Most people believe that the inner "imaginary" world is not "real" or not as "real" as outer waking reality because this is how our society has indoctrinated us. This is purely cultural and stems from our civilisation's current devotion to a limiting scientific paradigm based on the assumption that that an objective "real" and consistent external reality is all that really exists — all the rest is illusion.
By contrast, mystics, philosophers and holy men/women throughout the ages consider this external reality to be unreal, and that it is just a shadow-puppet show of a deeper reality. So what most consider real is unreal to many of those who have examined life deeply. But in our culture the inner "imaginary" world is believed to be a private illusory appendage to the outer "real" world.
If you hold to this worldview, as most Westerners do, then this is the first belief you must challenge in order to become a proficient system buster. This is because, by disconnecting the inner and outer worlds, we separate out mind from reality, a perspective that automatically rejects the possibility of mind being able to directly influence reality apart from direct "physical" manipulation via the body, and this belief has disempowered and enslaved humanity for centuries.
In truth, the mind is directly linked to the reality we experience because on a deeper level mind and reality are the same thing or process: all reality must exist in the context of consciousness. This is supported by philosophical interpretations of modern physics and by mind-over-matter interaction experiments.
One major resistance to putting attention on our minds (outside of deciding how to use them to physcially manipulate reality) is that we are afraid of delving too deep for fear of "stirring up" latent mental pathologies. We mistakenly believe that it is better for our sanity to regard the inner world, at best, as an entertaining delusional fiction, and keep a tight anchor on what we consider to be real. This is done by labelling the outer world as real or "reality", thereby dismissing the perceived dangers of the shifting sands of the inner world.
But the irony is that the "real world" is ultimately just as delusional, or conversely, the inner world is just as real. And just because there are mental pathologies associated with a small percentage of the population that are overwhelmed by the vivid reality of their subjective experience does not imply that the majority should avoid inner-focus. That would be like refusing to go out because a small percentage of people suffer from agoraphobia. Functional people are perfectly able to keep their sanity when travelling back and forth between inner and outer worlds without suffering some sort of pathological reality-bleed.
The few who question the illusion of reality have always treated the inner worlds as much more than just fantasy, and have used them as canvases to push past limiting belief systems. They have historically been the miracle workers, mystics, holy men and women, artists, revolutionaries, pioneers and brutal dictators. These are the individuals who are able to make a difference (both positive and negative) because their definition of reality is an empowering one. For them, reality bubbles up from our inner depths — the inner "subjective" world creating and defining the outer "objective" world. The veracity of this belief will always be questionable to doubters, but it is undeniably empowering.
So our definition of reality sets for us the limits of possibility. We all know that we have limitless choice in our dreams and our imagination, but few of us have the same confidence with our shared outer reality. It seems more fixed and objective, and we feel an obligation to play by the rules, rules indoctrinated into us by our culture.