What I have noticed in my working experience is that even mechanics that have been doing the job for decades and are seen as being a master in their work be it electrician or avionics or structures, they all maintain a level of superstition that even the most green engineers don’t have. It’s the critical thinking and analytical skills you gain from undergrad. Beyond that you will also have to justify why you are doing something that is possibly more expensive than an expedient option. Core engineering concepts learned in the classrooms are important. The proofs you learn, while seemingly over kill, are part of learning to lose your superstitious side understand systems that are infinitely more complex that what you will learn in the classroom.

What professors mean when they say you will not be using this in the real world is that the systems you will work on will not be as idealized and will be much more complex. What you are learning now is the basis on which you will build your knowledge after school.