you aint ready 

You are not prepared for what is about to happen to you. Your inadequacy is about to be exploited in a major way.

"Yo Nate. You tryin' to hoop?"
"I don't know, dawg."
"Why not?"
"I ain't tryin' to embarrass you like that."
"Boy, if you don't get over here and check the ball."
"OK. We can go but you aint ready..."

you aint ready by wordsmith_94 November 22, 2015

you ain't ready for this 

"You ain't ready for this" is basically a way of saying that this is so good you might not be able to handle it.

"I could tell you what happened last night but I bet you ain't ready for this"

"You gotta hear these tunes, you ain't ready for these tunes"

you ain't ready for this by TheeHitch December 10, 2013