In the days when I am making up the numbers in the human world. "The setting sun returns to the mountains and the sea" means that when the sun sets, if you stand on the mountainside or the seaside and watch it, it will be a feeling of gradually disappearing into the mountains or the sea. "Fireworks to the stars" means that the fireworks and stars in the world reflect each other, which is extraordinary. The source of the sentence "Mountains and seas, fireworks towards the stars" is the essay collection "The Days I Make Up Numbers in the World". The essay collection "The Days I Make Up Numbers in the World" is a collection of essays written by the modern writer Gu Nanyi. It was first published in 2021 Year, this is a book that reflects on human nature.