The significance of this story is that it shows how greed and the ambition to live above your means could lead to the destruction of ur future.
Matilda's obsession with social rank and riches led her to take desperate measures to "keep up with the Joneses" once she had her chance to mingle with them, thanks to the efforts of her poor husband. As she borrowed "The Necklace" she also borrrowed acceptance, admiration, social equality (though just for that night), and happiness. When she lost it and had to work 10 years to replace it, she lost her youth, any admiration, any acceptance, and all dignity (and her husband too).
When she realized that she had foolishly wasted all that time to replace that expensive necklace- and then finds out the original was a cheap copy-we assume that she also realizes the foolishness and waste of time it is to waste our own time and talent away trying to sniff after other people's lives. There is quite a remarkable significance in many ways;
The heart of the story is the ironic twist, the idea that the couple egaged in ten years of needless drudgery, that a moment or two of humiliating confession would have spared them a decade of slavery. But Maupassant is convincing in his swift characterization, for instance, in the husband’s “triumphant air” (paragraph 7) when he presents the invitation to his wife, in the wife’s unexpected (but to us natural) expression of “disdain” (11), in the husband’s embarrassment that he had not thought about what she might wear to the affair (15–18), in the wife’s “intoxication” at the ball (54) and then her shame as she leaves, dressed in the “modest wraps of common life” rather than in the furs of the other women (55).
Notice, too, Maupassant’s unsentimental (is it cynical—or merely realistic?) statement that her years of drudgery coarsened her (“she went to the fruiterer, the grocer, the butcher, her basket on her arm, bargaining, insulted, defending her miserable money sou by sou”). All these skillful touches of characterization raise the story to a level far above a merely ironic anecdote.
Maupassant then darkens the tale when the couple leave the ball, first by the wife’s thoughts about her wraps, then by the difficulty they have in finding a cab. From here on, things go downhill swiftly.
Maupassant from the very beginning prepares for the outcome. For instance, the very first paragraph speaks of “destiny,” more specifically of “a mistake of destiny.” Admittedly a reader does not put much weight on this phrase at first but on re-reading, it takes on significance. There is
something odd, something almost unnatural or freakish, Maupassant suggests, in the fact that this pretty, charming girl was born into the class she finds herself. Further in this paragraph we are told that “she let herself be married to a little clerk,” that is, she seems to have no will of her own; her fate is settled for her. And surely we all realize that although we feel we are acting freely, chance plays an enormous part in our lives: Had we gone to a different college, we might well now have a different spouse, and we might be engaged in a different career. And (unless we smoke cigarettes) we do not choose to fall ill or to die the way we will die.
For the most part we feel as though our actions are free—we may think we are the captain of our fate, the master of our soul—but most of us probably recognize that in many ways we are puppets.