How did Zhuge Liang borrow his life? Why did it fail?

In Romance of the Three Kingdoms Seven Stars, Kongming lit a lamp in Wuzhangyuan to prolong his life. Zhuge Liang said, "If the main light doesn't go out within seven days, my life can be extended by one year" (the first year is 12, which is a commonly used number in China), but in the end Wei Yan quickly recorded that the light went out. This matter can be found in Romance of the Three Kingdoms 104. During the Three Kingdoms period, Zhuge Liang attacked Wei and made six trips to Qishan, which took a lot of effort and soon became known. Later, he entrusted the generals. Jiang Wei said that the method of praying for longevity is used to save fate. Zhuge Liang set up a seven-star lamp and walked around beating it all day. Sima Yi looked up at the starry sky and knew that Zhuge Liang was dying, but he was not convinced, so Xia Houba led the troops to explore. Unexpectedly, Wei delayed thinking that he had robbed the village, and hurried to the tent to report that he had trampled out the lamp of the life core monument. Zhuge Liang threw a sword and sighed: life and death have a life, and you can't pull it. Jiang Wei tried to cut Wei Yan, but Zhuge Liang stopped him, so he told him that Sima Yi had not come to rob the village, but to see my life and death. Zhuge Liang died in the army after telling the funeral. Sima yi heard that Zhuge Liang was dead and the Shu army was defeated, so he set out to catch up. Jiang Wei and others used Zhuge Liang's idol to launch, scaring Sima Yi away, and the Shu army returned to Xichuan.