Why do we need to learn courses that are not related to our major in college life, such as why students who prefer to study polymer materials should learn mechanical design?

supplementary question:
Why do universities students need to learn some courses that have nothing to do with their major, such as polymer materials students who are partial to research, why do they have to learn mechanical design?

No best answer

Because our professional attribute is the nature of engineering, and mechanical design is not in vain, mold designers are a big choice for our future employment.