I suppose you could say that the most important message in the story is that nothing is quite what it seems. What we unthinkingly call "real" is actually no such thing and is always a good deal more complicated than we think it is. Marquez's writing style is magical realism, which means that, although it appears realistic on the surface, it is actually infused with fantasy to give us a deeper understanding of that reality.
On the face of it, the events of the story are pretty simple and straightforward, if more than a touch bizarre. But that's not the half of it. Like life itself, life in this remote town is a good deal more complicated than we might think.
Take the eponymous old man, for instance. We might expect him to be shown to be an angel or exposed as a charlatan straight away. But that doesn't happen. Instead, and in keeping with the overall message of the story, he occupies a position of considerable ambiguity throughout the story, veering back and forth between angel and con man...
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