For a long swath of history, pre-modern, the term "enlightenment" was used in a Perennial Philosophy sense. By this I mean that it was NOT used to describe a vague, ill defined, near impossible to attain, "new age" status of being. It(enlightenment) referenced a well defined mental model or worldview, often experienced during mystic states catalyzed by plant medicines in the form of psychoactive brews("mixed wines").

Initiates were intentionally introduced during banquets, seasonal rituals and at house churches. The mental model described as enlightened might alternatively be termed, TRANSCENDENT. Differentiating it from the default state, EGOIC mental reference frame. Briefly, EGOIC describes our usual sensibility that we travel across time guided/steered by an individuated and free willed, steersman or homunculus that resides within our body/mind. TRANSCENDENT describes an EXPERIENCE during which our usual control agent seems to loosen it's grip or even "die". Hence the term, ego-death. Self control is felt to be rather illusory as one experiences, no separate self and no(or little) free will.

The particulars of these mental models are well described at the following site for those interested. The important point is to articulate that, enlightened or transcendent mental model is  an experience that will be had by most people if appropriately catalyzed. The EXPERIENCE is true, whether it reveals foundational insight or Truth is a personal question.

So described, enlightenment is neither rare nor difficult to attain. How one uses the particular reference frame to inform their mundane, daily life is the stuff of tomes.

[URL unfurl="true"]http://egodeath.com/EntheogenTheoryOfReligion.htm#_Toc177337620[/URL]

Peace