The paper argues that what is left behind in the current era of accountability is the educational content. The authors present shedding the content as the great challenge of teaching and learning in today’s schools. They turn to the tradition of Bildung and outline the theoretical background for the content-focused approach to (research on) teaching and learning. Their approach is based on analyses of authentic (real-life) teaching and learning situations. The paper highlights how didactic case studies can be used to generalize the findings across individual cases. Within the multiple case studies, 44 didactic case studies were reanalysed to identify didactic formalisms, i.e. problems in the semantic and logical structure of educational content, which corrupt the quality of instruction. Two specific types of didactic formalism are described in detail; stolen cognition and concealed cognition. Stolen cognition prevents cognitive activation of students when the teacher over-reduces the space allowed for the students’ cognitive work with the content, concealed cognition are instances of purposeless cognitive activation of students due to their being disconnected from the content.