I'm so sure
Used sarcastically to express one's doubt. A: "He really has a crush on you, I swear!" B: "Yeah, I'm so sure! Like the captain of the football team would ever have a crush on me, please."
I am so sure!
Inf. I am right! You are way rad! I am so sure! This is too much. l am so sure!
I am so sure!
exclam. I am right! (California.) You are way rad! I am so sure!