Previous research has adopted various approaches to examining teachers' and students' relationships to mathematics. The current study extended this line of research and investigated six prospective elementary school teachers' experiences in mathematics and how they saw themselves as learners of mathematics. One-on-one interviews with the participants were conducted, and their written reflections were collected. A grounded-theory approach and a framework for analyzing mathematics identities were adopted in data analysis. The findings showed that the participants' development of obligations-to-oneself was associated with not only their opportunity to exercise conceptual agency but also their aesthetic experience with mathematics. Their views on themselves as learners of mathematics had cognitive, affective, and "aesthetic" dimensions. The findings suggest that teachers and students can engage in a reflection on their aesthetic involvement in doing mathematics. There is a need for a local theory of aesthetics in K-12 mathematics.