Not sure I'm accurately understanding your point here. Are you saying that "I" (my awareness) was itself experiencing "anxiety / neutrality / coldness", a mental formation which it finds gratifying--- worth grasping ---despite its not-so-obvious unpleasantness?
Well, yes, in my experience, there are many ways I can be asserting myself in meditation, versus training the mind to be singularly attentive to its object.
Basically, I could be sitting with a mild unwillingness, so maybe I have thoughts of chores and work coming up.
Or I could be sitting with excess-yearning-for-something-"meditative"-to-happen: this kind of yearning, a pressing for something to happen could cause me to create mental formations that were anxious/tense/expectant and cold (sometimes both mentally and physically, sometimes just mental aloofness/cool remove, sometimes just physically cold or chilled) or conversely, ecstatic and warm and exhilarating-- neither of these are jhana, they are just me wanting something and so, yes, some sort of mirage experience is created, like a sci-fi movie builds a great monster or fairy by showing an incomplete and an only-hinted-at picture: that is a wonderful movie trick.
It's excellent to notice these suggestive stories and the sensations. And then to just return to the object, as in the breath, if one is practicing anapanasati (or on another being if one is practicing metta,etc).
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Could it be that this mental formation appeared with a particular purity because it was detached from physical and/or emotional phenomena which it is usually blended with? Actually I was wondering where this neutral coldness came from, and it hits me that it came from me, and only from me
I agree with this: these are created mental formations.
***That's normal and it's good to see what's happening. However, if the mind is not willing to return its object of training (say the breath, either body wide or at the nostril-lip area) then clearly the mental formations are more gratifying than the training in mental stabilization and absorption.
It's okay. It is very normal that the way of using the brain that has gotten one through life ~ a director ~ is not quite ready to stand down and release the steady streams of gratifications it gets from directing itself and framing everything.
So to go into meditative training, one is asking the the directing brain to sort of go get a massage and not tell the masseuse what to do. Just keep asking the mind to lay on its object, so to speak. Just stay at the object: breath in, breath out, breath in, breath out, breath in, breath out.
This is not a trance. This is steady attention and lessening any straining to do cultivate steady attention (sometimes by using with countermeasures like gentleness, friendliness, gratitude, etc). Anapanasati is a whole remedy system to countering tension/strain: training the mind in a pleasurable way to come to equanimity.
It is very normal for the mind to rebel against this: it is a very simple game, not the usual constant directing-&-gratification cascade the mind usually coordinates for itself around objects. Still mind is asked to truly welcome just laying its attention in the object, like someone very agitated receiving a massage is asked not to keep jumping up from the table, but to enjoy just the simple activity, just relax and stay with the object.
This is also why I respect and really like your practice of holding you son's hand during his nap. Just breathing. just breathing, just breathing. Director-mind may, too, decide to take a nap into the hammock of its attention-object. breath.
I'm looking for some quite orgasmic rising sensation, but if piti is a sensation of well-being when sinking in one's own depths, then definitely I've found piti.
I think piti is a very athletic feeling. Sometimes the energetic sensations can actually seem to accumulate in the groin because a) that's gratifying and the mind is used to directing traffic (experiences) in ways that it knows are gratifying and b) because the sitting posture certainly has the groin just wide open.
But if that doesn't happen and the energy is allowed to build, sometimes the energetic sensations seem to accumulate in the head area and that can be alarming: is my head doing to explode?
Finally, piti can just be allowed to become suffusive, fully saturate the body everywhere and that, to me, feels "athletic"... but everyone has their words for this.
Eventually, that arising of energy will pass and like a high tide and stormy water going back down, what is left behind is a very comfortable, even low, steady, suffusive comfortableness; one may not even know where hands and feet are; like high tide and storm waves that have washed away sand castles, piti leaves behind deeply, calm sukkha and can seem to have washed away mind's connection to its own body markers (locations of hands, feet, knowing where arms and chest are, etc). Now with sukkha, one is experiencing deep calm, maybe even breath is very subtle--- and this can be very provocative for the mind anew ("Where's my breath!?") or maybe one is not worried about finding the breath now, just letting the mind steady itself here in subtle "terrain",
***like a small boat on a black night drifting: one doesn't want to fall asleep, but also one does not want to sense the darkness in a way that would fabricate sound-sight-feeling-other objects from the just-darkness. Here one just gets accustomed to losing the breath and letting mind be okay with not having that subtle object, and so on.
Anyway, just my thoughts. Clearly you know the practice is yours, training with mind-to-object, not looking for anything people have said or written for themselves.
I'm quite shocked to read you speaking about fourth jhana. I don't think I've been able to reach even the first one! (...) on the other hand you're speaking about fourth jhana.
I just raised that because you wrote:
"I wondered why everything was so cold and neutral at this point, it bothered me quite a bit. I felt stuck, unable to move further. It was neutral but not equanimous because I was disturbed and thinking and wondering." By raising the word "equanimous" I thought you were raising the topic of jhana that is suffusively equanimous -- just raising it, not suggesting it had happened. So I just wrote about it in general and in support of your point: equanimity doesn't have disruptedness in it