Meng Po Bridge, what's the story?

In the ancient legend of China, Meng Po was the messenger responsible for erasing the memory of the living in the underworld. There are usually three theories about the origin of Meng Po:

When the HarmonyOS system was first opened, the world was divided into three areas: heaven and earth, and heaven was in charge of everything. This world is the so-called Yang world, and the earth is the underworld. The boundary of the three realms, whether in heaven or in the earth, the immortal and the yin official, each performs their duties. Meng Po was already on earth when he left the Three Realms. She used to be a scattered official in heaven. Later, because I saw countless grievances and hostilities in the world, I refused to let go even if I died. I came to the Forgotten River in the underworld, set up a cauldron at the bridgehead of Naihe Bridge, and refined the lingering thoughts of the world into Meng Po soup for ghosts to drink, thus forgetting the love and hate before my death, unloading the burden before my death and entering the next reincarnation. This statement first appeared in Taoist classics in the Spring and Autumn Period. In China's traditional thought, it means "people die like clouds", "die once" and "don't remember the kindness of the dead".

Second, the so-called Meng Po is Meng Jiangnv. After Meng Jiangnv went down the Great Wall in tears, she saw countless bodies under the Great Wall and could never find her husband's bones. In order to forget these painful memories, Meng Po Tang was made to make people forget. Later, God missed her feeling of missing her husband and saved her from the pain of reincarnation. Let her cook Meng Po soup by Naihe Bridge, and let the ghosts involved in reincarnation forget everything in their previous lives. The so-called "past lives have passed, and good and evil in this life are only from the mind." Meaning. This statement has been widely circulated since the Yuan Dynasty, and it is often seen in the notes of scholars in the Ming and Qing Dynasties. It is also the most widely circulated statement among the people. In many legends about Meng Po, this statement is quite realistic.

Third, Meng Po was born in the Western Han Dynasty. He studied Confucian books since childhood and began to recite Buddhist scriptures when he grew up. When she was alive, she never looked back and never thought about the future. She just wholeheartedly advised people not to kill, but to be vegetarian. She was a virgin until she was eighty-one. She only knows her family name is Meng, so she is called "Granny Meng Po". Later, Meng Po went to practice in the mountains until the later Han Dynasty. Because people who knew the karma of past lives often revealed secrets at that time, God appointed Meng Po Laonai as the god of the nether world, and built a platform for her to forget. In this legend, Meng Po is actually not an old woman, but a peerless beauty. The reason why Meng Po first made Meng Po Tang was to forget his past. Meng Po's only memory is to send a bowl of Meng Po soup to ghosts coming and going on Naihe Bridge.