Knowledge Management Systems (KMS) are predominant in both theory and practice. However, are the same systems discussed in theory actualised in practice? By comparing and contrasting KMS in theory and practice, this paper demonstrates that they are indeed dissimilar. In theory, KMS have both subjective and objective components. In practice, only the objective component of KMS appears to be actualized; hence, these KMS in practice are essentially Organisational Memory Systems at best and not KMS at all. By unravelling the mystique of KMS, this paper exposes a fundamental anomaly. Further, an apparent void currently in practice is highlighted; namely, the lack of the subjective component of KMS in practice. KMS in practice are being heralded as key systems that are vital for organisations to survive and thrive in the intense competitive environment of the Information Age. Surely then, a KMS in practice that supports not only the objective component but also the subjective component of knowledge management would indeed be a truly powerful system?