The most heretical thing I have entertained about arriving at spiritual realization is that it's a memory. Nothing can be more controversial
than to say that everyone, including all the great masters and Buddha himself, had profound temporary realizations that changed their perspectives completely, and then became just memories. So many teachers talk about that period of bliss or grace after enlightenment that lasts days, weeks, months, or possibly even years. They also share that at some time it settles back into humanness. Up and out, then down and in - back to ground, as Adya says. What if that back to ground is the return to distracted awareness that is no longer free from mind, no longer centered in the present eternal moment? That its drawing on a powerful memory to sustain the idea that it is enlightened? What if the experience of enlightenment cannot be sustained by a human being? Then there is no reason to worry about "losing" the awakening because all lose it! Hm think about this....think deeply on it.
Going further I think that experience does have to be profound enough keep something. I consider that it may be a sort of "reverse trauma" in that it is imprinted on one's conscious awareness enough to be lived over and over, except that it is a positive imprint, not the haunting nightmare of conditions such as PTSD. There is a sort of "graduation" into this constantly repeating memory of such a profound realization. A chapter could be written on this.