Our world's social conventions are, by & large, egoic inventions. I did not use the term 'creations', for the ego cannot create anew, merely change, modify or adapt (Truly 'distort') true creations. Entropy is Truth for the ego. Much of our societal, political & cultural stratifications & distinctions are invented/distorted in a telephone game style process. Understanding 'class' and 'nobility' in light of this situation can be confusing. Etiquette has become a tool of egoic minds to demonstrate 'value' to others. It is not entirely inaccurate to refer to manners, politeness, 'being nice', etc. as an exercise in external validation. Tis better to be 'real' than 'nice', but let us not forget that our True Self is actually kind. Kindness can largely be found in the eye of the beholder, and this is the heart of Nobility of Spirit.
True nobility cannot be accomplished by ego alone, no matter how much energy & effort is expended towards this aim. As we come to identify with our infinite & True Self, we chip away are our egos, molding them into fine marble sculptures from the rough ashlar of their temporal origins. Nobility is sovereignty, magnanimity, nothing to lose. Egos cannot create, and therefore no ego can effort to be generous without an ulterior motive, or they would soon be destitute. The ego can give until it hurts, for it will indeed hurt at a certain point. The mystic (those living beyond ego, or perhaps 'behind ego' is a more apt description) can afford to detach and abandon all, even up to and beyond Death, for he/she is ever in touch with (connected to) their inner source of energy & manifestation, the Divine Spark of True Nobility found (although at times buried) within each of us.
Each of our egos has the potential and inclination to lead us straight into the demonic manifestations of Fear-based living. I encourage you to look up the etymology of the word 'demon', as an interesting aside. Essentially, a demon is an egoic invention (thought-form, or ego itself) with a limited (but can be perceived to be great or intense) level of access to Divine energy driven to use this to cause harm, motivated by inner Fear(s). This accurately describes some (perhaps most) humans, and demonology is largely a matter of degrees. 'Casting out demons' is done by reconnecting the 'wiring' to another's inner Divine Spark. This is accomplished through the 'exorcist', by their own Divine Spark, the healer allowing energy to flow through their body, and may be 'allowed' to direct this procedure, but cannot (well, should not, for their own safety) claim that their egoic self holds power over anything. Sovereignty is reserved for the Divine Principle, not our ego nor our persona(s). This can be a huge balancing act for the mystic, shaman, 'actualized' person, etc.
Class, etiquette and manners can be attempts by the ego to pretend to be True beings, to replicate the Joy, Love & Compassion of our True Self. As part of the personal growth transformative process, this is healthy. However, when employed to avoid or prevent personal growth, by pretending our rough ashlar is a completed work of Beauty, this can cause Harm (pain, suffering, evil, etc.) 'Keeping it real' can be an egoic demand to deny growth and be recognized as sufficient (which egos cannot be by definition), or it can be an honest acknowledgement of the Earthly state of our persona(s) and ego that we are working diligently to shape.
We are all Beautiful, Peaceful, Loving Beings full of Light & Life, each handed a broken-down (distorted) set of bodies, personal habits, mental & emotional programs, habits & false ideologies from which to form ideal reflections of our Higher (True) Selves. Manners, etiquette, elegance & class can be employed as tools to create patterns of behavior in our temporal conditions in order to shine forth our Love & Truth. This is their redeemed purpose, let us learn to enjoy them appropriately. We act better because we are (True Self) better, not to 'become' (ego) better. But, at the same time, we do 'become' (behavior) better, 'increasing' (cleaner mirror) in value to meet our everlasting Absolute Value.