When I met my first student, Pasco, he'd just danced an old net dance to give luck to a fishing fleet. He thought it was all just silly superstition, but he needed the money. I was with my uncle who was recovering from a heart attack and needed gentle exercise and we came across them on the beach. As soon as I saw what he was doing I knew it was magic, but he refused to believe it. No one had ever really heard of dancing magic - my later research really only drew up a small tradition in a far eastern country, though my foster mother happened to know of one herself.
Since I couldn't convince him, he continued to go about his life as normal. He came from a harrier family - law enforcement - and he and his cousins of the same age had training in the afternoons. I believe they were teasing him, and he accidentally performed a spell that raised them all three feet into the air... and just left them there. Nothing he or anyone else could do would bring them down. He had to come all the way to the Duke's citadel to fetch me for help. And even so, he still didn't want to believe that he had dancing magic!
I did go, of course, but I left them there for a while while I talked to his elders about the situation. It seems that while some other kind of magic might have been acceptable, something that could be turned to use as a harrier, dancing magic was simply so outlandish that he's soaked up the idea that it wasn't acceptable at all.
They did, in the end, allow him to take lessons, and I helped him figure out what he might do to reverse the spell. I don't think his cousins were at all impressed, though.