Whenever we read a piece of non-fiction writing that begins with an ‘I’, it is fair to assume that the writer is referring to himself or herself. It is similarly fair to assume, whenever we hear the word ‘I’ in the voice-over of a non-fiction film, that, in the absence of contrary evidence, the voice is that of the film-maker. Yet, even if we are in fact hearing the filmmaker speak, the identity of this ‘I’ is typically more ambiguous than it seems. In this chapter, I look briefly at the slippery brilliance of the voice-over in Chris Marker's Sans Soleil (1983) and then reflect on the far less successful engagement with voice-over in my own film Rohmer in Paris (2013), focussing in particular on two questions: who is the ‘I’ referenced in an essay film's voice-over, and how is the narrator's identity affected by who is actually speaking the words? By recounting the trouble that these questions caused me, I hope to demonstrate how central both the constructed identity of the narrative ‘I’ and the actual identity of the person saying ‘I’ are to the underlying question of how to communicate thought processes in film.