être né de la dernière pluie

You almost always use this in the negative form. You will say Je ne suis pas né de la dernière pluie. It is very rare to use it as a question or a positive statement. You can use it to react to a lie. You can use it when someone gives you a bad deal. It works perfectly when someone explains something obvious to you. It is your shield against being treated like a child.

Use it when a salesperson is being too pushy. Use it when a friend tells a story that sounds like a total lie. It is great for business meetings when someone proposes a suspicious contract. You can even use it in a text. If someone sends a 'scam' link, reply with this phrase. It tells the other person: 'Nice try, but I am smarter than that.'

Don't use this with your boss if they are just giving instructions. It can sound a bit defensive or rude. Avoid it in very formal ceremonies like a wedding. It is a bit too 'street-smart' for a black-tie event. Also, don't use it if you actually made a mistake. It is for when someone *thinks* you are gullible, not for when you actually were!

Water and rain often represent purity and newness in French culture. A 'new rain' implies something fresh and untouched. By saying you aren't from the 'last rain,' you are claiming history. This idiom became popular in the 19th century. It reflects a rural wisdom where farmers knew the difference between a fresh sprout and a sturdy oak. It celebrates the 'street-smarts' of the common person.

You might hear people say Je ne viens pas de naître which means 'I wasn't just born.' Some people also use On ne me la fait pas which means 'You can't pull that one on me.' However, the 'rain' version is the most poetic. It paints a picture of someone who has weathered many storms. It is a classic French way to stand your ground with style.