The course of the Loisels’ life significantly changed due to the necklace. When Madame Loisel lost the necklace she borrowed from her friend, Madame Forestier, she decided to replace it with a similar one instead of admitting the truth. The cost of the replacement necklace was beyond the Loisels' financial means, forcing them to borrow a large amount of money. To repay the loan, the Loisels had to live a hard, austere life for ten years. They gave up their comfortable apartment, dismissing their maid and moving into cheaper lodgings. Madame Loisel had to take up strenuous chores, and her husband worked extra jobs to save money. This prolonged hardship drastically changed Madame Loisel physically, and she seemed old and hard, a stark contrast to her earlier discontented yet simple self. However, after a decade of hardship, when Madame Loisel encountered Madame Forestier and confessed the truth about the necklace, she was informed that the original necklace was not real, and only worth five hundred francs. This revelation added a tragic irony to their life, as they realized they had unnecessarily lived a harsh life for a decade due to a false assumption about the necklace's worth. Thus, the necklace significantly altered the course of the Loisels' lives, demonstrating the sometimes disastrous consequences of pride, dishonesty, and materialism.