So long as there have been studies of philosophy and exploration of what could be, there have likely been questions of what defines different parts of humanity, including sex. Of course it was taught. The recent issue is acceptance of false realities. That a declaration or feelings make someone something he is not. Now that they can artificially obtain hormones and mutilate themselves to look the part in silhouette, we should accept that as "good enough" and agree "that man is a woman."