The Mass-Observation Archive at the University of Sussex sends regular "directives" to its panel of volunteer correspondents around the UK asking them to reflect on various issues relating to the day-to-day lives of ordinary people. Two directives from the 1980s and 1990s relate to libraries, books and reading habits. These sets of written responses are valuable resources for library history and information science researchers because they include the opinions of non-users, which are notoriously difficult to obtain using conventional research methods. The use of such an approach may help to counter some of the criticisms of current library history practices as being outmoded and irrelevant. Not only is library history undervalued by historians, it is also frequently dismissed within the LIS field in general. Linking library history to issues of current concern, such as non-users, may create opportunities to demonstrate the relevance of library history more widely. This article reports on the findings of a study of the directive responses, focusing on non-use of libraries, and highlights the implications for librarians and library historians.