person A: I was so very sure I'd aced my GCSE History exam. I'd written fluently and passionately for the whole hour_comma_ and I enjoyed it!
person B: Wow testing that is hard. Glad you enjoyed it.
person A: I enjoyed it_comma_ sure. I was very confident. The thing is_comma_ I totally messed it up. I got a 'U' grade - which I didn't even know existed!
person B: A "U" grade? yeah that's one that needs explaining