What a great statement to use to analyse this excellent short story! In a sense, we can rephrase this statement by refering to a common phrase or parable in the English language: "You make your own bed, then you have to lie in it." If we think of these two statements in regard to this story, and more particularly in regard to the character of Mathilde Loisel. The story makes it clear that she has every reason to be happy. Without any dowry or prospects, she is married to a minor clerk and is able to experience a comfortable life. Even though in a sense her marriage brought her "up" in the world, she lived as "a woman who has come down in the world." The beginning of the story makes it clear that she devoted herself to a feeling of dissatisfaction, rather than choosing to enjoy the relative wealth that she had:
She grieved incessantly, feeling that she had been born for all the little niceties and luxuries of living. She grieved over the shabbiness of her apartment, the dinginess of the walls, the worn-out appearance of the chairs, the ugliness of the draperies. All these things, which another woman of her class would not even have noticed, gnawed at her and made her furious.
Note the way that the text makes it clear that another woman of Mathilde's class would not even have noticed the things that place her into such a fit of grieving and dissatisfaction. The daydreams that she turns to as relief for her grief show that she is determined to not accept the reality of her state and cannot be grateful for what she has. Thus it is that we can argue the rest of the story shows the statement to be true. It was Mathilde's own greed for jewelry and for the appearance of wealth that led her to borrow a necklace from her friend, which in turn led to the loss of the necklace and Mathilde's subsequent falling into even greater poverty. Life is what you make of it, and Mathilde's refusal to be grateful for the simple luxuries that she had resulted in her loss of even those.