There is the myth that with enough knowledge and technology humanity can "manage the planet Earth" by further extending human domination, despite the increasingly apparent fact that the complexity of the Earth and its life systems can never be safely managed.
There is the myth that knowledge is increasing, although it is increasingly apparent that only some kinds of knowledge are increasing, whilst other kinds are being lost. In the confusion of information with knowledge, the myth has developed that somehow learning increases human goodness and makes people better, although ultimately it may be the knowledge of the good that is most threatened by all of the other advances sustained by modern education. It is quite probable that humanity is effectively becoming more ignorant of the things that must be known to live well and sustainably on the Earth.
There is the myth that humanity can adequately restore what it has dismantled, as typified by the modern curriculum fragmented into isolated disciplines and subdisciplines, of which a consequence is that most students graduate without any broad integrated sense of the unity of the systems through which life is sustained.
There is the myth that the purpose of education is to give individuals the means for upward mobility and success at a time when it is not successful people that are required but rather people capable of living well in their environments and capable of struggling to make the world more habitable and humane.
And there is the myth that modern human culture represents the pinnacle of human achievement, which is a dangerous form of cultural arrogance in a period of cultural disintegration.