The use of technology to support learning is well recognised. One generation ago a major strand of human--computer interaction research focussed on the development of forms of instruction in how to interact with computers. Today, however, the advanced usability of modern technologies has all but removed the presence of many user manuals. Learners, educators and developers now need to know not how to use the technology per se: the adoption of user-centred design has solved much of this. Rather, they must understand the nature of learner behaviour across contexts: insight is required into "how to learn" using mobile technology and "how to manage and structure" learning behaviour across changing contexts whilst mobile. To this end, we advocate a reinvention of effective user instruction at the metacognitive level, and use a classic framework developed in the early 1980s to structure our conceptualisation of the onward research and development effort that is required for 21st century user instruction and support.