Mathematics and applied mathematics are the most difficult majors in undergraduate mathematics department. Just look at its course. The major of mathematics department is 1. Learning analytic geometry, advanced algebra (specialized course 1), mathematical analysis (specialized course 2, known as the enhanced version of calculus), girls' mathematics department scores better (because MM works hard). There is nothing wrong with studying hard. Their specialized courses include abstract algebra (basic number theory), real variable function (one level more difficult than mathematical analysis), functional analysis (derivative of real variable function), topology (basic graph theory), differential geometry and numerical analysis.