I don't believe it proves anything "mystical" or "transcendent".
Thank you for reciting your experience. Whether or not it proves transcendence is the question that I just cannot find an answer for, and I am grateful (though not glad) for you adding this comment. The "meeting of the minds" that you had sounds very similar to a story I heard from a friend using LSD. Acid trips are often used by people attempting to reach higher levels of conscious (such as, I think, the original lead signer of Pink Floyd) These levels of conscious are also similar to what has been described by people with Schizophrenia. In some cultures mental illness has been seen not as a illness, but as being a higher level of spirituality. It will be interesting to know if we can ever find "proof" that there is a mystical level, or if it is simply the result of a cocktail of mental chemicals.
we lack a common positive conventional vocabulary and/or imaginary reference system -- e.g., "I identified to consciousness itself" or "I was born again" -- to make sense of it.
A very enlightened comment. Regarding the term 'born again', I wonder how experiences compare between cultures. On the one hand, those born again within a Pentecostal Church may not be experiencing the same effect. On the other hand, maybe their experience is similar and it also may be similar to completely unrelated cultures, such as African voodoo trances. I doubt when a JW becomes born again though, that they have quite the same depth of experience.