滄海桑田

Etymology
Originally. From  (神仙傳·麻姑):

Idiom

 * 1) time brings drastic changes to the world; the vicissitudes of life

Descendants
Others:

Etymology
From 🇰🇲. Borrowed from, literally “the blue sea turned into mulberry fields”.

Idiom

 * 1)  drastic changes in the world