This post also makes me wonder if there are any (possible, not necessarily already discovered) generalized strategies for detecting unknown knowns, or at least unrecognized default behaviours,

Compare your beliefs and behaviors with those of people who are succeeding at things which you are not. (And which, presumably, most people in your culture also do not succeed at.)

For example, if you (and most people) aren't wealthy, consider the beliefs and behaviors of those who are.

This doesn't always give you a route to change, of course. I have noticed that most people who are standout successes in any sort of internet-marketed, information-products business (or at least, the ones I want to emulate) seem to personally (and quite sincerely) value various forms of philanthropy, and many of them claim it's impossible to be really successful without it, despite the lack of any logical or direct connection between the practice of giving, and their personal getting.

This drove me crazy for years, both because the often-mystical justifications given simply made no sense to me, and because I simply couldn't wrap my head around the idea of personally wanting to give money or time away without a direct return.

However, I changed something else in my personality earlier this week -- a particular incidence of learned helplessness -- and afterward, charity suddenly made sense to me in a way that it simply never had before, and I actually found myself being happy about the idea of e.g. contributing to local libraries, and I actually gave some money (out of pocket and spur of the moment) to my regular hair stylist, upon hearing that she'd just been diagnosed with breast cancer and would be struggling financially in a few weeks, post-surgery.

And I felt good about it.

Anyway, this particular change makes me suspect that philanthropy is actually a shibboleth -- while it is correlated with success, there is actually a separate trait driving both the charity and the success, and that it has something to do with lacking certain types of "victim" mindset (one of which I got rid of this week).

So I'm now curious whether I could actually refrain from charitable acts and donations and become more successful... even though my preference and active interest now, is to contribute to certain causes. (And not on a utilitarian basis -- it's strictly warm fuzzies -- something that, AFAICR, I've never experienced before.)

But I'm not sure whether I want to make that particular sacrifice (holding off on the charity until "wealthy") in the name of science or not, especially since there are so many other potentially confounding variables, and in any case I lack a true control.

Anyway... what was I saying? Oh yeah. Compare your beliefs and thought processes with those of people succeeding at whatever you want to do/be/have, to identify what "non-default" settings they're using. Pay special attention to how they think, in the sense of types of processing steps and what emotional attitudes they seem to hold, rather than merely what they think, which often sounds like the default wisdom if the person has not, themselves, thought deeply about what they do differently.

IOW, it's less about "belief" than about "process". What do they do differently in their heads? That's where the gold is.