Definition & Meaning of "be over the moon"in English

What is the origin of the idiom "over the moon" and when to use it?

The origin of the phrase "over the moon" can be traced back to early 20th-century England. The exact origins are uncertain, but it is believed to have originated from the idea that the moon is associated with a sense of wonder and enchantment. This idiom can be used to express intense happiness in relationships, such as falling in love or experiencing a significant milestone.