First, I'll explain what I mean when I say core idea of a work of fiction. It is the concept that the fictive work tries to be communicate (be it a poem or a piece of prose) through its metaphors, symbols, similes, plot, characters, etc. This idea can be a moral, or it could just be an interesting idea. I'm limiting this to fictive works, as these are the works in which one is traditionally told the ideas shouldn't be explicitly shoved down someone's throat, whereas in factual works, it should be made as clear as possible.
Sometimes I worry that the plot, characters and literary techniques in a work of mine don't paint a clear enough picture. Sometimes I don't. I think I've found out what kind of properties make a work susceptible to this kind of concern:
- The idea it tries to convey is quite complex, and thus less likely to be understood.
- The way I try to convey it happens to invoke other, unwanted ideas that may be mistaken as the core message.
As for (1), I'm not implying that the reader can't understand the concept (although with very complex ideas, that too is a concern). Thing is, just because the reader can understand the concept, doesn't mean they can infer it from a bunch of metaphors and whatnot. I feel like the simpler the concept, the easier it is to communicate clearly through literary techniques. However, the more complex concepts are also able to be communicated these ways, but it requires subtleties that I feel either go unnoticed, or are too ambiguous.
Now sometimes, I like making ambiguous art. I like leaving interpretation up for the reader. However, this is when I've interpreted my work in multiple ways, finding entertainment and meaning in those different interpretations, and suspecting that there's more interpretations to be had. Sometimes however, I have a very clear interpretation in mind, and although it's often fine that other interpretations are had, I don't want anyone to miss that one intended interpretation. Other times however, I recognize that the work is in a kind interpretative mine field, where a lot of the other interpretations are not just unintended, but unwanted: this is what I mean by (2).
So, here's my question: is it okay to create work that is dependent on a separate, explicit explanation? As in, it can be enjoyed without the explanation, but when enjoyed as such, it will likely be misunderstood, or be experienced as without deeper meaning. Then, the explicit explanation, available in some way or another, is read, and thus a new experience of the work is had. Basically, the work is acceptably enjoyable in isolation, but the work isn't truly experienced without the extratextual element.
Some of you may be tempted to say: if you don't have the ability to communicate the message, then you simply don't have the ability. You may say if a work that is split into two elements, one implicit (the story or poem), and one explicit (the explanation), that's a bad short-cut. However, that is dismissing the possibility that there are ideas out there that cannot be "safely" communicated through fiction, meaning no matter the author's ability, it would always require an explicit explanation to be truly understood. And what's so bad with a work that is first read by an uninformed reader, before being retroactively understood (and potentially reread) via the explanation, giving the reader aha moments and letting them appreciate the ways of communication that the work displays, despite those communications being insufficient in the absence of explicit explanation?
Here are some examples of where context was needed for the work to be experienced properly (a), and where an explicit explanation was needed for the work to be understood, and thus experienced properly (b).
(a) 13.43 to 15.39 of this video
(b) This poem and it's subsequent explanation in a comment (see the long one made by OP in response to a commenter's questions)
EDIT:
I want to say that I'm looking at this from the perspective of someone writing a smaller work. These issues are most relevant to smaller pieces, as one has less material to communicate the idea (with a long novel, a complex idea is easier to get across, as one can drive the point home more strongly with repetitions and looking at the idea/moral from many different angles). Furthermore, the proposed solution of using an extratextual element to explain a confusing piece, and try to motivate the reader to reread, isn't likely to work with a novel. I think most readers would stop reading, as existing in a long state of confusion and uncertainty, as would be created by a convoluted novel, isn't enjoyable. And then to expect the casual reader to actually reread it shortly after the explanation is also unrealistic in my opinion. A confusing short story or poem however, can actually be quite fun.
So, definitely respond to this question with general comments about fiction of any length, but I'd like to encourage responses focused on shorter fiction, as I think that's most relevant here.