Both dancers and lovers of recursive approach to allegedly or actually inaccessible goals may both turn around in circles. But be careful! It does not have to be a precise circle. Perhaps its center moves slowly or it is in reality a weakly pronounced ellipse or a spiral. It is precisely a small deviation, which quantum mechanics of the avant-garde described as a perturbation a hundred years ago, that perhaps makes up for the spice, which, incidentally, does about the same in a beautiful dance.