How much meaning the above line holds today. To remind us that the one constant in the universe is change.
A little prodding around on the internet revealed to me many stories that are thought to be the origin of this phrase. The most popular of them seems to be one about King Solomon.
One day, when he was low, he asked his ministers to go look for a ring that he had seen in a dream. It made one feel happy when one was heart-broken, and sad when one was happy, he said. His ministers set out in search of such a ring and eventually one of them met an old jeweler who carved into a simple gold band the inscription, "this too shall pass."
Another version of the story says he sent one of his ministers, Benaiah, to look for such a ring, to humble him. After months of search, Benaiah, decided to take a walk in one of the poorest quarters of Jerusalem. He passed by a merchant who had begun to set out the day's wares on a shabby carpet. "Have you by any chance heard of a magic ring that makes the happy wearer forget his joy and the broken-hearted wearer forget his sorrows?" asked Benaiah. He watched the grandfather take a plain gold ring from his carpet and engrave something on it. When Benaiah read the words on the ring, his face broke out in a wide smile.
This too shall pass.
I'll leave you with a poem and some songs here and here.