How do expressions and sayings come to be?

Answer by  km8738 (1917)

Expressions and sayings come to be, generally, over use over a long period of time. That use is usually spurred by its practical application at one time or another. That application is usually directed towards a current event that is popular enough to create a commonly used phrase which can later be applied to other events as well.

Answer by  johnresa (2455)

Well sometimes someone says something and others may find it cool or catchy and eventually their friends are repeating it and the cycle is continued. That is the origin of so many expressions and sayings being so widespread.