Background: The research on which this article is based was commissioned because of concerns about perceived shortages of willing and able young people choosing to study physics at university. Purpose: This article reports on first year physics undergraduates' narratives of why they are studying physics and uses these narratives to identify reasons for their choice. Design and Method: Narrative-style interviewing with a purposive sample of first year undergraduates yielded data that revealed complexities around decision making, including choice of university course. Analysis of the texts was informed by psychoanalytical notions rooted in the work of Sigmund Freud. These psychoanalytical notions were used both in generating the interview data -- the undergraduate volunteer interviewees were conceptualised as "defended subjects" -- and in analysing these interviews in order to conjecture how unconscious forces might figure in young people's decision making. Results: After analysing the interviews with physics undergraduates, with respect to the question "why are they reading physics?", the claim is that identification with a key adult is an important element in an individual's participation. On the other hand, we discerned no evidence that experience of the sorts of innovation typically designed to increase physics uptake -- for example "fun projects" or competitions -- had been key with respect to a desire to read physics. Conclusion: Attempts to recruit more students to university to study physics should note that a young person who identifies with a significant adult associated with physics, typically a teacher or family member, is in a good position to believe that physics is a subject that is worth studying.