o fo sho - When you're so sure of something you might as well be scream

When you're so sure of something you might as well be screaming it at the top of your lungs

I'm o fo sho, I just ate a whole pizza by myself and I'm not sorry.

I'm o fo sho, I just won a bet and now I'm king of the classroom.

I'm o fo sho, I just told my mom I'm never eating cereal again.