Why is the ending of Mo Bosang's novel The Necklace unexpected and reasonable?

When reading a novel, I was surprised to see such an ending, because after all, it was the hero who worked hard for so many years to earn so much money back.

But in fact, it is because of the heroine's inner arrogance-pretentious, just because of her face, so she is so vain. It's not a bad thing for a woman to have a little vanity, but it's very bad if she goes too far. Then her fate will be changed and turned upside down because of her vanity.

Life needs an ordeal to polish a person's defects.

But in fact, it is often fate that makes people sad.

It makes sense because if that necklace is really worth that much money, will the "rich" rich people lend it to such an ordinary or even poor little housewife at that time? The answer is no.

It is inappropriate for the lady to lend an expensive necklace to the heroine so easily. At least one IOU? Is there a deposit? It's so simple, so there is a problem. Read the full text again, and you will find that the ending of the novel is "unexpected and reasonable".