Hi Paul,
Not disagreeing that satipatthana is for those with more understanding, but it cannot be stressed enough that for each of the ways to dwell recollecting the body in body (kāye kāyānupassī viharati) there is the following guidance:
…this way he abides contemplating the body as a body internally, or he abides contemplating the body as a body externally, or he abides contemplating the body as a body both internally and externally. Or else he abides contemplating in the body its nature of arising, or he abides contemplating in the body its nature of vanishing, or he abides contemplating in the body its nature of both arising and vanishing. Or else mindfulness that ‘there is a body’ is simply established in him to the extent necessary for bare knowledge and mindfulness. And he abides independent, not clinging to anything in the world. That is how a bhikkhu abides contemplating the body as a body. - MN 10
So, it isn’t so much that one just relentlessly observes postures (or breath or anything), but uses them to discern the body to that necessary extent.
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Bringing this back to the topic, a layperson can - as described in AN 11.12/13 - recollect various things (sati) for the purposes of joy and eventual samadhi, but that capability would not apply to cases of being directly focused on specific tasks with the intention to complete the task successfully. I have little doubt that joy on account of those recollections would contribute towards clarity and diligence, and therefore allow a person to perform their duties well, but it is important to attribute those qualities accurately to the basis from which they arise. In other words, a person who frequently recollects worldly goals and desires (which is not a Dhamma specific practice), and has a clear understanding of them, has a higher probability of performing a task well (pending they possess the skill and/or determination to do it), but it is equally likely that a Buddhist layperson, also possessed of the same skill, but accomplished in the joy associated with their good conduct and understanding, would be able to use that to their advantage to perform a task very well. There is a key difference, however: while both are partaking in the principle of recollection to consolidate their effort, the former is using clarity of desire as fuel while the latter - established in joy (on account of virtue) - is inherently more comfortable and less susceptible to anxiety and distraction.
In the end, a person who partakes in the principle of recollection, but does so without knowledge or experience of the Dhamma themes, is not capable of tapping into joy to the extent described in the suttas, which results from not only recollecting those themes, but having recollected one’s own development of them on account of previous effort. We cannot forget that there is both wrong mindfulness and wrong samadhi, which may both contain a degree of joy available on account of being established in things that have nothing to do with the eightfold path. Anyone who has experienced the so-called “flow state” can attest to being able to establish the mind upon something that may be entire sensual or environmentally dependent. By all means go for it if accomplishment in that respect is meaningful, just don’t mistake that for the rapture available on account of work in Dhamma. There is rapture available on both sides of ignorance, which is a very crucial thing to bear in mind (cf. SN 36.31).