One year - maybe 3 , 4 years ago I was at a the CSIA convention. There was a level 4 Charles Martin - he is from the Maritimes and he was very good skier leading a class where my friend was. They had a whole day module and he was skiing with the class for a whole day. During lunch up at the mountain at Tremblant, someone had taken on of Charles's skis by mistake. So he skied only with 1 ski all afternoon with them. He recovered the ski at the end of the day somehow when the other person returned the skis to the rental shop. Quite amazing.