I heard it in an Adele song (He won't go), and I know she's using not-exactly-proper english sometimes (like "she ain't gon' be"), but I can't tell if I've just never heard it or if it's not correct.
Is it OK to say in an informal conversation?
Here is the verse from the song (full lyrics here):
So petrified, I'm so scared to step into this ride,
What if I lose my heart and fail the climb
I won't forgive me if I gave up trying
I heard his voice today
I didn't know a single word he said
Not one resemblance to the man I met
Just a vague and broken boy instead