He wasn't born yesterday!


He wasn't born yesterday!
I/he/she wasn't born yesterday! something that you say in order to tell someone that a person is not stupid and cannot be easily deceived.

You'd better think of a better excuse about the dent in my car. I wasn't born yesterday, you know!

You can't expect your mother to believe that - she wasn't born yesterday!


New idioms dictionary. 2014.