I wasn’t born yesterday is an idiom with a murky origin. We will examine the meaning of the common idiom I wasn’t born yesterday, where it came from, and some examples of its idiomatic usage in sentences.
I wasn’t born yesterday is a remark one makes when he feels he is being taken advantage of. I wasn’t born yesterday is a way to say that one is not naive or gullible; that one is instead, experienced and wise. The expression is used when one is skeptical of another’s intentions or abilities. The phrase I wasn’t born yesterday came into use in the late 1800s, but the exact origin is unknown. A famous American book, play, and movie, Born Yesterday, boosted the popularity of the term. A humorous variation of the idiom is I was born on Tuesday, but it wasn’t last Tuesday.
The title turns the rebuttal “I wasn’t born yesterday” on its head, so that being young and artless is a position of privileged insight. (Los Angeles Review of Books)
But because I wasn’t born yesterday, I know they’ll face obstacles that my son will never have to worry about. (Yakima Herald)
I sip my Diet Coke (which is really a Diet Pepsi that the waitress tried to pass off as Diet Coke, but, ahem, I wasn’t born yesterday) and watch a montage of dudes and various balls fly across screens. (Washingtonian)