This article is concerned with the representation of memory in sf films at the beginning of the twenty-first century. It will examine three films in particular: Michael Winterbottom's Code 46 (UK/US 2003), Michel Gondry's Eternal Sunshine of the Spotless Mind (US 2004) and Wong Kar-wai's 2046 (France/Germany/Hong Kong/China 2004). These films are concerned with the complexities of chance encounters and elusive relationships, highlighting themes of memory, love, nostalgia and longing. They follow on from an earlier tradition of sf films that focus on memory's subjectivity, preoccupied with the use of technology in creating false or prosthetic memories. The films examined here, however, focus less on the details of technology used in manipulating memory. Instead, their concerns are with the blurring of the distinctions between remembering and forgetting.