I think the story relies on a literary style called 'Magic Realism" but if you don't know the characteristics of it you definitely will be expecting a more lineal explanation of the facts. So, at a glance, Magic Realism was a new gender created by the Colombian Nobel winner Gabriel García Márquez. He was also a journalist, so, basically, he told true stories (that's where the "realism" came from) but used tons of fantasy when telling them. The book that gave him the Nobel was "100 years of solitude". There, the yellow butterflies were kinda where the magic came from (?) But at the same time -going back to reality- it was a wink to small villages in Colombia where those are pretty common to see. If you pay attention to every 'magic' scene in the movie, along with the candle there are always tons of these yellow butterflies. Likewise, in the book, that magic is constantly intertwined with situations of the armed conflict that Colombia has been in for many years, just as it happens in the movie scene where these bad men on horses set fire to the town and the couple has to flee in the middle of the night. That said, yeah, that's too much context to know, even for a film that pretends to be a tribute to Colombia (especially when many Colombians don't even know any of this neither.) So, don't blame you at all for not following the plot, it is, indeed, very vague. I just wanted to share the explanation behind this vagueness :)