"I wasn't born yesterday!"
I wonder if others might provide answers regarding the idiomatic phrase: "I wasn't born yesterday", meaning that the speaker is not naive, or easily fooled about something.
I recently watched a film from Columbia and a character pointed to her teeth, to indicate playful scorn at something another character had said to her. She said: "Son de leche" (I think!). I imagine this translates as "they're milk teeth", like a young child would have. I wonder why she didn't say: "No son de leche"?
I have read the phrase: "Yo no me chupo el dedo", from "no chuparse el dedo" (to not suck one's thumb), but I have not heard it used.
"No nací ayer" and "No me chupo el dedo" are very much used idiomatic expressions. Let me give you some examples:
Me dijo que en España era una actriz famosa, pero ¿qué se cree? ¿que me chupo el dedo? (meaning I know she's not telling the truth!!)
Me quiere hacer creer que no le importa lo que piensen de ella... jajaja ... Yo no nací ayer eh!!! No le creo ni ahí (this is a very popular expression in Argentina meaning I don't believe her, not even a bit)
I've heard someone say ¿crees que nací ayer? so it is pretty straight forward! I haven't heard the other tho.