I didn't know you were chill like that
It's when someone is being a total annoyance and then flips to being calm like they just won a million bucks.
You were honking at me like I was your worst enemy. Now you're giving me a peace sign? What's your deal?
You were yelling at me for cutting you off. Then you just gave me a hang ten. Are you trying to confuse me?
You were cussing me out in the car. Then you just went chill. What's with you?