I have an example i will never forget. As a student one of my tutors also taught english classes to the chinese exchange students. One day she got our class to come sit in with them and she basically just asked me to play a piece on the piano. I was out of practise and played the only piece i could remember at the time (no sheet music) which was rondo ala turka. I had many, many mistakes, it was fairly embarassing but i just laughed it off. Until one of the chinese girls asked if she could play something. She proceeds to go up, and play the EXACT SAME PIECE i just muffled my way through and she played it PERFECT. it was like a slap in the face.