The paper combines an autoethnographic approach with a literature review of general and discipline-specific research linked to the theme of cross-curricular citizenship education ("CE") from the 1990s to the present. It identifies 20 reasons why cross-curricular CE struggles to take flight in secondary schools. These reasons are organized into four categories: structural, epistemological, attitudinal and pedagogical. While the focus is mainly upon citizenship education in England (and, to a lesser extent, in Australia), the paper suggests that the barriers identified exist in most nations.