First year ME student. The importance of being able to derive complicated equations?

I'm close to being halfway throughout my first year of mechanical engineering, and it's been pretty neat so far!

Recently in mechanics, we've started to use many equations that have a "core equation", well actually, we've been doing that since day 1. To derive at these equations requires some derivation and integration, and thorough conceptual knowledge of issues. A simple example of this would be using basic equations of circles (together with the equation for shear stress and torque) to arrive to the equation for the maximum shear force (which includes being able to derive the polar moment of inertia).

I find myself understanding the steps, but the books I use now lack detail when it comes to deriving equations, and as a result it takes me quite a while. Is it just because they're trying to acquaint us with how specific formula's are related to more general ones? Is this something I should be able to do as a first year student or will this be introduced throughout time?

Many thanks!

EDIT: Read all the responses and all I can say is that I came to find out much more than I intended to with this question. Thank you everybody!