When I was teaching English in Huwei, Taiwan, I was trying to explain to my students that I was very sensitive to caffeine. I told them if I drank tea at 9 pm, I would be listening to up listening to music and banging my head at 2 am. When I demonstrated head banging, they asked why I was doing that thing with my hand. I tried to explain, but I wasn't at all sure of the origins myself.

They said, "That is what the priest in the Taoist temple does when he summons the god."