Digital curation emerged as an important new concept in the theory and management of cultural information, not least because of its broad applicability and promise of a universal approach to ensure future "fitness for purpose" of digital information. This paper explores curatorial traditions in the field of museums and cultural heritage, in order to contribute to the active current debate on the nature, scope and methods of digital curation. It uses an approach inspired by cultural-historical activity theory in order, firstly, to understand current digital curation practice, its achievements and limitations; secondly, to explore key activities in the cultural heritage field, i.e., knowledge production in archaeological fieldwork and publication, museum curation, and meaning interaction in exhibition visitor experience. On account of these insights, it concludes that, in order to ensure the declared objective of future "fitness for purpose", and avoid the risk of epistemic failure, more effort should be dedicated by the digital curation community on developing adequate knowledge representation of digital information in specific epistemic and pragmatic contexts; that an agency-based approach, using event-centric approaches to represent knowledge on the content and context of information, would be particularly useful in some application domains; and that formal methods to curation lifecycle based on belief change and ontology evolution could also be used in modelling the co-evolution of the epistemic content and context of curated knowledge.