… you study design and art all of your life.
You go to art school and learn about 
     color theory
            typography
                  font matching
balance
     the need for the eye to rest on white space
             contrast  ….

And you take all of that expertise into your work and design a kick-ass website, only to hand it over and watch all of the fine details you nurtured and brought to life slowly disappear in the CMS website that anyone can log into and change once you have finished your build.