Yeah, it's true that some folks wouldn't have a hard time rattling off their budget, emergency fund and other areas of their finances, but that doesn't mean everyone can, because I'd bet that a lot of people wouldn't have a single clue as many folks out there are only trying pretty hard just to make it to the next paycheck without having to overdraft.
I am painting the scenario of an hour or two discussion, but yeah, they might have to access some of their documents and maybe they might need help to write them all out, while at the same time, as long as they know basic math and common sense, I am presuming that most of them (like 80%, should be able calculate out if they have discretionary income and/or more income than expenses), and yeah, maybe they cannot do it without some coaxing, but they surely are capable of going through those kinds of basic maths and common sense processing of logic.. which means that that they are capable of learning and capable of figuring out whether they have $100, $10 or some other amount of discretionary income within this particular week). It is like an ability of someone who is feeling a craving to smoke some cigarettes or they have a friend that would like cigarettes as a gift, and within a short period of time, they can figure out the extent to which they have $10 to buy the cigarettes or not..... just meaning that the cigarettes are not a necessary expense but an extra optional expense.
Yeah, figuring out whether one have discretionary income isn't actually rocket science, and you're not also wrong for pointing out that with a little bit of guidance and of course some basic maths skills, figuring out one's discretionary income shouldn't be much of a big deal. If someone can be able to calculate whether they can actually afford a pack of cigarettes or not, then they can pretty much figure out their discretionary income, it's just simple arithmetic and common sense, even if some folks are actually retards, and needs others to help them calculate their expenses every single time, it still doesn't change the fact that anyone can actually do it.
As long as folks can learn to prioritize needs over wants, and of course also have a clear picture of our finances, then learning to track one's expenses and income, and of course making more informed decisions about their finances should be a piece of cake. And with a little bit of support, folks shouldn't also have a problem developing their skills and of course confidence to effectively manage their finances.
And it's important to note that this is really not about being a financial expert or having some sort of degree in economics, It's more about knowing how/when to add and subtract and most importantly, knowing how to make better decisions when it comes to income allocation. I believe it's also possible for folks to achieve all these on their own, when given the right tools or maybe by also getting a little support from others, either ways, it's more than possible for folks to learn to do this and of course, make progress as they advance towards achieving their financial goals.