Each of us, should we be persistent in doing the Great Work, will enjoy peak experience to the point that we have a life changing epiphany. I do not mean those small moments of realization we get as we go along. I am talking radical changes in perspective so all-encompassing that it is impossible to live with any other would view. Within the new viewpoint, a sense of self emerges that is so complete the random insults of the world fall impotent against one's understanding.
In my case, I have the perfection, the unfolding, and the wholeness. I know that my daily practice must include purity (not in the context most think of it) and continuity. Other people will have other understandings. Though, in reading Merton's New Seeds of Contemplation, I was amused to learn that my understandings parallel the great mystic with some consistency.
There is something odd that happens though. Out of left field, one starts to reminisce of the past. You start to feel that old emotion and want to go back to who you were. Funny thing, you never do. You can't. You are not that way any more. In order to go back you'd have to be beyond indulgent. It would require a willful decision to be less than you are. I cannot imagine anyone doing that.
I mention this because a couple of my friends have had the same experience lately. I have some theories as to why this happens but nothing definitive enough to write here.