Abstract-User experience (UX) has been defined in several ways. In general terms, it refers to everything that is individually encountered, perceived, or lived through. The literature on UX reports studies mostly focused on specific interaction events, which may have an impact on the user's emotions and feelings. This paper provides a reflection on how UX evolves over time. We performed a medium term study comparing four types of UX: Anticipated, Momentary, Episodic and Remembered (or Cumulative) experience [1]. Anticipated UX refers to the period of time before first use, and focuses on the expectations a person has on the product, service or system. Momentary UX refers to any perceived change during the interaction in the very moment it occurs. Episodic UX is an appraisal of a specific usage episode extrapolated from a wider interaction event. Remembered UX is the memory the user has after having used the system for a while. The different facets of UX have been analysed in a medium term research spanning over four weeks. The study compared the experience of ten users of a pedometer/fitness app that counts steps and burned calories all day long. The results show that the experience of use changed over time decreasing significantly before, during and after the interaction. The evaluative judgment related to the overall satisfaction with the product, was largely formed on the basis of an initial high expectation on pragmatic aspects (i.e. utility and usability) before and during the first encounters. After four weeks of use, the problems related to usability, reliability of data, and battery drain became a dominant aspect of how good the product was perceived. Hedonic qualities and Attractiveness were negatively impacted as well. The continuous reflection on the use, documented in online diaries, made the problematic aspects prevailing on the overall UX in particular on the evaluation of Episodic and Remembered UX. This prevented any change in behaviour in the participants.