In rethinking what is theoretically conceived as a 'gap' between what young people learn in sexuality education and what they do in practice, this article argues for the need to comprehend young people's sexual knowledge from their own conceptualisation of this. Drawing on empirical findings from research with New Zealanders aged 17-19, young people's own understandings of their sexual knowledge are explored. These findings indicate how young people in the study conceptualised sexual knowledge in two ways: as information derived from secondary sources such as sexuality education, and knowledge gleaned from personal sexual experience. Hierarchies were evident within and between such types of sexual knowledge, in terms of the status young people afforded, and the interest they displayed in them. The type of sexual knowledge young people were most interested in, and which they identified as lacking in sexuality education, centred on a 'discourse of erotics'. It is argued that the inclusion of this discourse within sexuality education programmes might offer one way of closing the knowledge/practice gap, by raising the status of sexuality education's messages for young people and drawing this information closer to their lived sexual experiences.