In this paper we introduce a participatory design technique for early, formative concept evaluations to elicit in-depth user feedback and suggestions, revealing attitudes and motivations of users. The technique is motivated by the link between memories, experiences and dreams, and is based on the assumption that users can make better judgments about novel design concepts if they link them to their past experiences. The technique involves user sessions consisting of two main phases, one focusing on recollecting past experiences in related contexts, and one focusing on envisioning future experiences that can be enabled by the use of the concept. In both phases, designer-user dialogue is established through storytelling. Storytelling is used b...