I've done both over the 20+ years I've worked. Initially I learned admin skills as a back up when earnings in my first career (professional brass player) got skimpy (I have NO talent as a waitress and HATED doing retail sales). I really enjoyed working with temp agencies with different assignments, so that worked out well.
I have since retired from playing professionally, and am an executive secretary by choice. All my experience over the years in office environments and organization and planning as a free lancer makes me REALLY good at what I do. My boss is thrilled with me and my work, and has rewarded me appropriately and accordingly.
I learn something from everyone I deal with, be they transient or dinosaur. If they are difficult to deal with, well, OK. It may be unpleasant, but it just adds to my repetory of skills on dealing with people (and to my repetory of guerilla skills as well).
Movingonup, I have found over the years that NOTHING you learn or do, either from books or from experience, is ever wasted. You never know when you will use something. You may be using it now and just haven't realized it. So, please don't think your education (book and otherwise) is wasted.
Thanks for letting me spout. I'm looking forward to seeing other posts on this.
