A review of literature reveals that self-efficacy (SE) has been shown as a successful predictor of students' course-taking. Many factors have been reported to have influences on physics self-efficacy (PSE), but most of them are contextual variables. This article suggests that learning content is also an influencing factor. Physics learning content in high schools is far from being congruent with girls' development of cognitive psychology and social cognition. This incongruence contributes to the lower PSE of girls, and consequentially leads to their less course-taking in physics. The relationship is examined with respect to the author's personal schooling experiences in China. Appropriate interventions to promote female students' physics course-taking need to be emphasised. (Contains 1 footnote.)