In this paper we investigate the issues of user attention management in the context of the changes of underlying metaphors in human-computer interface design. After the introductory part, we discuss the problems of staying focused as well as reconstructing the context of an interrupted task while working in some computer environment. We highlight the problems with current interfaces and the desktop metaphor in particular, we propose that the mind-prosthesis metaphor may be better suited for the design of future, attention aware systems, and we put forward some guidelines for interface design that follow from our analysis.