This is the way I explain the phenomenon you are referring to:
As we all know Witnesses have a term called "Individual Spirituality" and this spirituality can be measured by the individual and others "qualified" to and of course everyone else can attempt to.
The WT ALWAYS tells you to keep in the busy work. Personal Study (using WT literature), Prayer, Field Service and Meetings. This takes up a large chunk of your free time and for some who work a lot almost all of it.
The WHOLE framework of the Witness life is designed to condition and indoctrinate. "Individual Spirituality" and Indoctrination are interchangable terms.
When the WT refers to the lowering of ones Spirituality they are actually referring to their conditioning taking a weaker hold on your conscious mind.
If you miss meetings, even for a short time, your "closed eyes" open up just a little and you can see the light of day, just a little.
Once you have the "eye slits" as I refer them to you always have the possibility of seeing the inside of the Kingdom hall for what is TRULY is.
I believe that the Kingdom hall is where the "awakening" happens most. The KH is a creepy scene. Very rhythmic and repetitious, everyone is nodding their heads and look as if they are just SOAKING up something they have never heard before.
You take a look at those nodding heads. Then you listent to what is being said. The content is dry and is the thousandth time you have heard this particular part of the conditioning and maybe the ten thousandth time the person you are looking at's time.
"What the hell IS this?"
It's a freaky and liberating revelation.
I believe that this CANNOT happen spontaneously. It might have felt spontaneous, but likely it was the climax of a long process, but the Awakening is the most memberable and life shattering.
In order for this to happen, you have to have a "low spirituality" which again, is synonymous with "lower indoctrination."
-Sab