Enterprise Resource Planning (ERP) systems implementations undertaken all over the world have resulted and continue to result in significant organizational change. Organizations adopt ERP systems to benefit from the underpinning (allegedly) best practices, the suppliers’ or sometimes consultants’ “recipes” for conducting successful business. Such practices are said to lead to considerable improvements in the way the business performs, emphasizing the functioning and management of business processes. However, the implementation and use of best practices remains highly problematic! Here, we conceptualize ERP’s best practices in terms of organizational routines, which are considered to be “repositories” of organizational memory. Memory mismatches are at the core of our (metaphorical) lens to surface understandings of what goes wrong and how people negotiate solutions, both during the implementation and, more importantly, the in-use phases of ERP systems. Looking from an organizational memory mismatch perspective provides us with interesting insights into the challenges and opportunities for implementing and managing change in this context, giving an appealing structure for reasoning about ERP’s best practices. Illustrations from a case study of a Dutch SME are presented to enrich our account. The overall thrust of the paper is to identify a variety of concerns, intriguing questions and avenues for future research.