From a practical point of view, Pei Zhi's mother may think that there is no way out to learn mathematics, and Lao Lin next door is an example. But Lao Lin next door gave up the opportunity to study abroad and his dream for Lin, and finally became an accountant. If Lao Lin had chosen his dream, he would not just be an accountant now, thinking that Lao Lin's talent would make good achievements in the field of mathematics. Peizhi's mother asked Peizhi to learn boxing again in order to keep her healthy.
In fact, it is written in the novel that Pei Zhi's father suffers from mental illness, which is caused by the madness of learning mathematics. Moreover, this mental illness has a genetic history, which means that Pei Zhi may also suffer from this mental illness. Pei Zhi's mother didn't let him learn math to protect him.
However, no one has ever asked Pei Zhi's opinion. Peggy's father died because he studied math, which makes no sense at all, so she won't let her children learn math. Did his father really die because he studied mathematics? There should be other factors, but Peizhi's mother mistakenly thought that it was all because of studying mathematics.