We often feel that our engagement with our more hidden self is that of a war. We think that we can only gaze into ourselves insufficiently and that we may never know who we truly are. I think that we underestimate our understanding of ourselves, and we too frequently downplay our assessment of our strengths and weaknesses. However, knowing who we truly are is a task that few completely actualize in a single lifetime. I doubt that I'll ever be able to see my purpose fully manifested in my life as this particular being, but we can rest assured that we'll always be able to consistently understand ourselves more and more if we set the intention to do so.
On Ideas - What is the nature of an idea? One could posit that ideas are the effects of brain activity. But how can an idea translate into the creation of things out in the world or influence the collective moral codes of civilizations? Plato suspected that the idea was the highest form of being. This means that ideas are realities that form the superstructure of total being, and physical forms are nearly imperfect renderings of overall existence. It is difficult to define ideas without generating dispute; we know that how language corresponds to "facts" or "values" can impede us from understanding the reality of things. Ideas are one such concept that can convert into a bleeding mess of contentious pickings at semantics and definitions, etc. I suspect that the ontological status of ideas might be discernible through how they affect physical reality. We humans tend to find the physical world apt to present factual sets of information to us, so naturally seeing ideas become physical reality, e.g., inventions, buildings, infrastructures, etc., can help us to recognize the power of ideas and how they seem to possess innate substance divorced from the physical world. Whether or not ideas have some kind of ontological resting place is debatable, but somehow they are engaged with every aspect of our experience, at least those aspects of our experience that are the result of our own ingenuity.
What is the Sole Doctrine? I have devised a single principle that might be useful to you. I dub this the Sole Doctrine. It is simply a truth that has emanated from many spiritual and philosophical disciplines: Our self-identification is, in reality, an identification with limitation and form. Even identification with consciousness in general can be a false equivocation of the true Self. In reality, the true Self doesn't adhere to restriction, as we ascribe toward ourselves ever too naturally. We are unified with the state of Being regardless of our level of consciousness, and beginning a spiritual path with that proposition in mind will allow us to eventually strip away our false constructions of who we are and move toward fuller freedom and replete identification with Being.

On the Limitations of Understanding -

Our individual and collective faculties used to grasp reality appear to bear many insufficiencies. Firstly, Kant shows that the noumenal world, that realm of existence behind our sensory interpretations, is wholly inaccessible. This instantiates a problem, whereas we can only know what information is presented to us via the phenomena. Therefore, our understanding in this area is to some extent impeded by this perceptual limitation of ours.
We as biological beings, tying in with us only largely having access to sensory phenomena, are restricted by both the limits of our brains and also the limits of the world our nervous systems happen to exist in. A 4th-dimensional being, or even a supposed superhuman with vastly superior intelligence, can conceive of the nature of reality in a much more nuanced and succinct way than we can. However, biological impediments to understanding may be waived with the development of neurological enhancers or perhaps innovations to our genetic composition.
Lastly, we face the problem of knowing the metaphysical. As showcased by the noumenal-phenomenal distinction, we struggle to gain direct insight into aspects of reality that aren't empirically or logically (in a traditional sense) evident. The objectivity of numbers or even God has been the subject of fiery debate for millennia, all primarily due to many metaphysical disagreements. If we were simply equipped to detect metaphysical content like empirical phenomena, then we would perhaps be able to settle several pressing disputes that still haunt philosophy to this day.
In considering what is possible, negate all the constructions of this particular world. Imagine existence with no restraints, even those of space, time, and causation. In doing so, you'll find that what is possible is truly boundless and that we human beings are capable of imagining this fact, even if this said imagining is quite limited.
Philosophical consciousness—that means of inquiring into all levels of being and phenomena—takes precedence in those individuals who dare to apply a critical lens to all thoughtforms that relay our own collective and personal understandings. Without philosophical consciousness, we would be deprived of the tools necessary to scry all realms for truth, and we would therefore remain blind to it. This faculty of humanity, gifted by nature, enables all of us to find those diamonds of truth in the rough of deceit and illusion and, through its power, take us back to who and what we really are.