Mathematics is full of mystery. We illuminate the myth to expose two conflicting senses of mystery at work in mathematics and its education practices. There is a sense of boundlessness with mathematics--the idea that we never fully know. There is also a practice of concealment, in which an answer or solution is known by special people who may support or provide a scaffold for students' navigation to the "special" knowledge, but may also challenge their access to it by erecting barriers and boundaries. In remythologizing mystery, we identify that the valorization of mystery in mathematics is rooted in the wonder of exploring boundless landscapes and is used misleadingly to justify school mathematics with the other sense of mystery--uncovering the concealed.