I think one of the best tests you can take is trying to explain your dad what do you do if you work in a marketing or advertising agency (if you want the expert mode, try your grandfather).
Recently I spoke about my work with my father, and I found it to be a fascinating conversation from where I withdrew a good insight regarding what I do. The main issue here was what is it we actually do when we work with social media, what's the point for the company with whom we work and how do we determine the value of our service. He just wouldn't get the point of it, and I was getting frustrated by not being able to explain myself properly.
And then I finally got him to understand a little better: I told him we sell both the know-how and the time our client doesn't have to do the stuff we do. Could the client ever do it? Of course, given the right information and attitude, the right dedication to follow the right sources and establishing in your mind a point of view regarding your industry, and given the fact, of course, he'd have the time to do all that and still do his work and manage his brand on so many other levels.
We sell time our client doesn't have to do the work himself. Of course, you have to know how you'll properly invest that time in order to produce remarkable work, because otherwise, sooner or later, you're on a highway to losing your client and there's no speed limit.
Is this a basic way of viewing things? Is this all in the book? If this service providing 101? Of course it is.
But then again, if you can't stripe down your line of work in a way that someone completely outside the industry can get what the hell you do every day, I'm not sure you really get it yourself.