Ah, now, I suppose conventionally speaking “you” may have come across Spirituality / Buddhism / Dzogchen / Zen as a means of dispelling whatever it is that ails “you” or perhaps of becoming “Enlightened” eh ? 🧐
Indeed, it’s possible “you” have already glimpsed-your-true-nature and are seeking a deeper “understanding” of what “that” was eh ?
Oh, as you can see “non duality” forms part of the Title of this website thus the practice of (non dual) “Contemplation” features heavily in a lot of the Content so IF you really are interested in “what it is all about” please be prepared to do some research on words, concepts and terms which are presently unfamiliar to you eh ?
This is most assuredly not an Intellectual exercise 🌟
A Short Commentary on the Three Statements of Garab Dorje by H. H. Dudjom Rinpoche
I. As for the direct introduction to one’s own nature: This fresh immediate awareness of the present moment, transcending all thoughts related to the three times, is itself that primordial awareness or knowledge (ye-shes) that is self-originated intrinsic Awareness (rig-pa). This is the direct introduction to one’s own nature.
II. As for deciding definitively upon this unique state: Whatever phenomena of Samsara and Nirvana may manifest, all of them represent the play of the creative energy or potentiality of one’s own immediate intrinsic Awareness (rig-pa’i rtsal). Since there is nothing that goes beyond just this, one should continue in the state of this singular and unique Awareness. Therefore, one must definitively decide upon this unique state for oneself and know that there exists nothing other than this.
III. As for directly continuing with confidence in liberation: Whatever gross or subtle thoughts may arise, by merely recognizing their nature, they arise and (self-)liberate simultaneously  in the vast expanse of the Dharmakaya, where Emptiness and Awareness (are inseparable). Therefore, one should continue directly with confidence in their liberation.
Translated by Vajranatha
Baudhnath, Nepal, 1978
From : The Golden Letters (John Myrdhin Reynolds)
 It’s just like the immediate dissolution of Snowflakes as soon as they fall into Water eh?
Now, AFAIC prior to the arising of all thought, all images, any sense-of-self, any-thing-whatsoever is what’s meant by one’s “true nature” (or “Original Face” in ZEN parlance) thus I hope you can appreciate why an Intellectual Understanding will never fully “get it” eh ? 🧐
Imagine that you had gone all your life without ever washing, and then one day you decide to take a shower. You start scrubbing away, but then watch in horror as the dirt begins to ooze out of the pores of your skin and stream down your body. Something must be wrong: You were supposed to be getting cleaner and all you can see is grime. You panic and fling yourself out of the shower, convinced that you should never have begun. But you only end up even more dirty than before. You have no way of knowing that the wisest thing to do is to be patient and to finish the shower. It may look for a while as if you are getting even dirtier, but if you keep on washing, you will emerge fresh and clean. It’s all a process, the process of (apparent) purification
From : Glimpse after Glimpse
By the way, it’s said for very very rare “individuals” (of whom ‘I’ am not one such unit-of-awareness) all that’s needed for their total-liberation-without-remainder is the “Direct Introduction” but as for the rest-of-us there must be some committed “practice” else such Realisation will remain forever as merely Intellectual Speculation eh ?
Ah, however for some, reflecting upon the question #WhoAreYou can seemingly “induce” the non-dual “state” eh ? 😉
Ah, here’s a nice summary, I’d say, of the difference between “worldly” self-centered-survival and what Buddhism / Zen point at : the actual nature of “reality” eh ?
From : Charlotte Joko Beck’s “Everyday Zen: Love and Work”