Memories, or, remnants of having had a dream ‘while sleeping’, are based on a hindsight assumption on behalf of a separate self in time; ‘I slept’, before ‘I awoke’. Yet sleep was not actually, directly, experienced.
These so called memories appear now only. In truth, nighttime dreams are a playing out, a reconciliation of the separate self of thought, with the true infinite nondual self, which being nondual is ever-lasting wakefulness.
The ‘mystery’ of sleep resolves only in that you are right now - asleep, and dreaming. The ‘nighttime dream’ is not dreaming at all, and the believing that it is only serves to bring a richness & fullness to This, the true dreaming.
As is always the case, all is revealed by the inspection & exploration of direct experience. You never actually experience sleep. There is but an apparent experience of others sleeping, and more truly bodies at rest. This, you internalize, and assume that you - sleep. As well, that you were born, are alive rather than eternal aliveness, and will one day die.
But never has there been a direct experience of death or sleep, upon which these assumptions are compounded, by the nondual infinite dreamer.
How enticing it is to now believe in states, such as states of consciousness. This too lends a profound lavishness of reality to your dreaming. Yet, absent of this illusory lux, The Truth lies bare, readily & plainly exposed.
All is revealed as the grand theater of your sole dreaming. The curtain-less-curtain rises and falls. The actors, the stage and the applause; you sit as always, in the front row, breaking your heart open again and again in your unfathomable stillness and unwavering perfection.