Nearly six hundred undergrads answered open-ended questions about why they'd purchased, downloaded or copied their most recently acquired album (the vast majority had acquired one within the last two weeks), and then they provided the same information again six months to a year later. ... The key finding was that only one in five participants gave a consistent reason or reasons at both time points. The researchers had anticipated that memory for some reasons might prove more durable over time than others, but this wasn't the case. Overall, the most common form of change was simply to invent new reasons at the later time point.