Pre-service mathematics teachers (PSTs) may hold different beliefs about school mathematics and university mathematics and different beliefs about teaching mathematics between high-achieving (HA) vs. low-achieving (LA) classes. Because of the differentiation, the beliefs relationship is complex. This quantitative study administered a questionnaire on 508 PSTs for secondary school from five Indonesian universities to investigate the differentiation and the complex relationship in beliefs considering the year of study. The data analyses reveal a differentiation of beliefs about university mathematics and school mathematics. Despite this differentiation, those beliefs correlate significantly and positively, indicating the tendency of seeing school mathematics and university mathematics with the same view. Similarly, although PSTs may hold different beliefs about teaching and learning in HA and LA classes, the beliefs in HA and LA classes correlate significantly and positively. Furthermore, we found that beliefs about university mathematics correlate with beliefs about teaching and learning in both HA and LA classes. We also found significant correlations between PSTs' beliefs with the year of study, but, unexpectedly, the correlations are very small. Reflecting on the results of this study, we discuss the necessity of designing courses related to university mathematics and mathematics education during university education carefully.