daily limits:

When weightlifting, there's only so much training one can do in a single day (and there are also weekly to fourteen day limits and even longer periodicity supercycles). One can't lift weights one hundred hours, in a row, and then eat and sleep for seven hundred hours, in a row, gain a ton of muscle, and then repeat. There are daily-ish limits after which one needs sleep (and food).

Brains (and the nervous system) aren't muscles, but there's something kind of similar going on, with meditation.

When one first starts meditating, one won't know what to do to produce efficient change, or even much change at all. (And, just to be clear/emphasize, producing efficient change involves a lot of non-effort and patience and surrender.) And then, over time, one gets better at producing change. (This is still not great wording.) And/but, at first, that initially constructive change will lead to grinding or jamming (if one unresponsively persists) sort of before even more fundamental limits get hit. Eventually generally avoiding grinding and jamming, via increased affordances and structural fluidity, one eventually learns to sort locally of max out an even "deeper limit," in a good and safe way, until the next time one sleeps. Doing this is sort of locally brushing up against a sort of "fundamental slack." Eventually, one learns to max out even this limit, in a few different areas, instead of maybe just one or two, almost in a widespread global sense, sort of sussing that out maybe over hours, until the next time one sleeps.

It's like there's "fundamental slack" and meditation eventually uses this up. And then sleep provides new fundamental slack for the next day. The more 90-minute cycles of sleep, the more new fundamental slack becomes available.

At first, this can sometimes be a little fraught. Like brushing up against it can lead to at least a little destabilization and/or almost narcolepsy. But eventually the system learns how to sort of max out this available change, while still apportioning exactly enough slack for doing, learning, interacting, in general, for other daily things.

There's a variable amount of meditation slack available, each day, it depends on day-to-day, in-flight structural features, as things unwind, move around, and settle. Sometimes it's a ton, even like twenty hours worth, but it's generally finite. Maybe every few months, for maybe many days in a row, there will only be five to twenty minutes of meditation slack available that day, until one gets another 4.5 to nine hours of sleep, and that's normal. Sometimes a twenty or ninety minute nap can unlock a lot more and sometimes not.

It may take quite a while to get a sense of this--for several years, one might not have the deftness, degree of fine-grain-ness / structural fluidity, something, to regularly bump up against this limit. And that's ok. It's a gradual process to kind of start bumping up against this limit (and to sort of suss out all available nooks and crannies that have remaining daily slack), and that's ok.*

While global wayfinding prowess is still developing, over thousands of hours (of including meta protocol-ing), it's a bit of a mixed blessing to be able to really use up daily slack, because it's not a guarantee that one won't be doing a mix of both undoing/untangling and tangling/entrenching. And it's ok if one is. It's a gradual process of moving the mixed ratio to more and more untangling/undoing.

So it's not even critical that one finds comes to get a sense for and regularly find their way to this limit. And again, it's not exactly the same thing as "having no moves to make that aren't grinding or jamming," though it's related--grinding or jamming is usually the next thing that happens once all "fundamental slack" is used up, though grinding or jamming can definitely happen long before that, too (and indeed is typically the thing that happens, if one persists unresponsively, and sometimes even if not--under unfortunate subterreanean momentum--before one starts reaching and getting a sense of this other limit).

"Grinding and jamming" is sort of just running out of local available "software moves" or not yet having some degrees of freedom or structural fluidity, speaking abstractly and too generally. And, on the other hand, this "fundamental slack" thing is sort of running out of available daily "hardware moves" or "hardware capacity."

Patience over days, and meta protocoling, can help sort out the differences and relationships between the two, and having a sense of the difference is definitely a useful input into global wayfinding (and, of course, global wayfinding applies both during and outside of "meditation," in whichever way that's narrowly, widely, or very widely defined, with "just lost in life," as an option, very withstanding.)

While it's not critical, one may eventually start getting a sense of this fundamental slack, and it does have some bearing on long-range efficiency over thousands of hours. And/but again, running up against this too soon, with too much "momentum"/​pushing/​forcing, before those sorts of things are long-run relatively untangled and integrated out of the system, can be a very problematic thing.

And, by the way, what is this phenomenon, neurologically speaking? I think it has something to do with local (high-dimensional) synaptic potentiation and depotentiation getting maxed out (or "minned" out). And then sleep (I forget which phase of sleep) does global synaptic renormalization [1], which makes those synapses available again. Sometimes it feels like it's "the same"** synapses getting maxed/minned out, over and over again, each day, over several days or even weeks, before things shift around to a new bottleneck. And sometimes it feels like sleep can only do so much renormalization, if there is that sort of a bottleneck, so those same synapses get maxed out again in like five to twenty minutes of meditation, sometimes in the early morning, if one starts meditating soon after waking up, while still in bed. And that's ok! Mediate bottlenecks happen.

What's particuarly interesting is how this phenomenon can be a thing, while, when it obtains, it's still possible to go about one's day and do various routine and important things. This says something about brains, and "load distribution," and "network"/"operational" dimensionality, and multi-network neuronal participation, and "content addressable memory," and malleability and ongoing spontaneous remodeling and didactic organisation [2], and structural fluidity, and all sorts of other things. (The previous list mixes scientific terms of art and my idiosyncratic usages particular to this document.)

And, sometimes it's too hard to have a "functional throughline," i.e. there's functional nonmonotonicity and one does need to stay in bed or only do light tasks, especially privilege withstanding.

In any case, bumping up against this "fundamental slack" starts to be a thing, and it's something one can kind of start planning around. If one bumps into meditation limits in just twenty minutes, a couple days in a row, then one might expect meditation will only be possible for twenty minutes the next day or two, after that, and so nonmonotonicity notwithstanding, one might plan more ambitious things in those next few days, to allow for more shifting and settling, more accumulation of fundmental slack (and non-meditative spontaneous reorganization!!!!!!!!!!!!), facilitated by novel, enjoyable, useful experiences, out in the world.

So this is one thing to keep an eye out for, in terms of meditative rhythms and day-to-day or week-to-week planning, of weaving meditation with other valued and "that's the whole point" sorts of things.

*

[1], [2] These terms, and others, are worth googling, on wikipedia, google scholar, and in other places. Quanta magazine has decent popular articles exploring some of the above, too. [Poke me and I'll get some more references, here, sooner or later.]

*Over time, one gets better and better at sussing out more places to "gently" use up additional fundamental slack, even after apparently having solidly run out (after which it's good to sort of gently stop on a dime, as best one can). So I don't mean to be too absolutist about this--sometimes it seems like everything is used up but then patient "non-meditation," for three hours, sort of floats up many more hours worth of things to do. This isn't too common, at least in my experience, but it's definitely also a thing. Usually it's better to just stop for the day. But if one has some spaciousness/slack, body-wise, and a relatively low degree of currently active "runaway processes," then sometimes, if one has a very light touch to sort of wait things out, without running into grinding, jamming, muscle tension, or other issues, then more useful degrees of freedom and slack becoming available, can be a thing. Again, this won't usually be the case, the better one gets at first-pass making use of what's available and the more structurally fluid, late stage, one is. But sometimes there's a little or a lot, with a very, very light touch and patience. The reason it's usually better to stop for the day is that there will be a tiny bit of slack left in the system, and that's sort of a safety buffer. If one kind of uses up that buffer, and then there's a bit of runaway momentum in the system, then inadvertently things can be pushed a bit too far, leading to muscle tension, and so on. And too little slack can kind of compound and make it find one's way out if runaway processes keep using it up, and so there's an increased change compounding issues and eventual high blood pressure, intracranial pressure, nerve impingement, and so on. So, it can be good to just let things go, depending on local concrete structural features of one's situation, at any given time.

**"The same" is in quotes above because maybe it is indeed the same physical synapses, maybe it's different synapses but the same pattern, as transferred through didactic organisation, and so on.