Hi Bryan
Welcome to the Dharma Overground! Take your time, don't be overwhelmed

Dharma Diagnosis is really hard when all there is is a single post to work from.
Also, judging from my quick web search for the word "naraka", I am totally unfamiliar with the conceptual framework you allude to, so probably not "naraka" as in "hell realm", right?
Generally, memories like this which are still vivid after a few years seem to be about shifts into new "territory" or mind states. Possible candidates from the framework I know best, which is the Theravada "progress of insight" described in great detail in Daniel's Book, would be: "Mind and Body" (because of the way you "saw" mental phenomena "in front" of you) or the ever-memorable "Arising and Passing" (because of the effortlessness and the way you seem to have stopped practicing afterwards). But it is really hard to tell!
My suggestion: start your practice again, if you haven't already. Discuss things here as they occur, when they are still fresh.
Cheers,
Florian