This article closely examines (a) the "representational" connotation which is often implicit in many analyses of the scientific knowledge which children have (or have not) acquired when they are asked to say or show what they know and (b) the still common-place presumption that recollections are akin to the extraction of ideas from a mental database. We demonstrate how recent findings in neuroscience reject traditional thinking about the nature of 'representation' and the character of associated imagery and verbal explanation. Researchers have to contend with the fact that concepts must be regarded as "flexible," and that memory is "dynamic." Such considerations emphasise the creative, rather than the reproductive, nature of remembering, thus calling into question the status of what is thought to be 'grasped' and 'imaged' by those being interviewed, possibly casting some doubt on the status of children's conceptions (and misconceptions) and the categories into which these are sometimes placed in schematic depictions of their understanding. Examples from research on children's cosmologies are used to illustrate the discussion. It is argued that science education researchers endeavouring to uncover what children know, intuitively and scientifically, through interviewing them, face a reconsideration of the theoretical underpinnings to much of their work.