What does Huang Li mean when he says, "When you die, you have to take it"? What does another sentence mean, "No one can live for a thousand days without letting a hundred flowers blossom"?

Hello, this netizen in Zhihu: We usually choose auspicious days of the ecliptic, days of death and red gauze as the evil days of the underworld, but it is not smooth for handlers to use the evil star underworld, so we choose this day less. The following is: people can't be wrong in 1000 days, (meaning relatively speaking), and there are very few flowers that can bloom for 100 days, don't you think! This is my understanding and I hope to adopt it.