It's interesting to consider all the different directions this thread has taken.
Words are flexible in the English language. Nobody practices medicine as a hobby, so "doctor" has a fairly uniform meaning. Yet, one can be a doctor of philosophy or recieve an honorary doctorate. Again, there are no hobby-barristers (that I know of), so we all have a fixed idea of what someone calling himself a lawyer does as his day job.
Drift over to an activity that can be performed recreationally and we have "pilot" who may only fly Cessnas and possess a PPL. Yet, fighter pilots, commercial pilots and airline pilots are not offended when someone calls them simply "pilot" despite the years of additional training and higher graduation of licencing.
I am likely the worst, least-knowledgeable photographer on this site. Yet, because I share a passion for photography and have carried a camera around in one form or another since acquiring my Kodak X15 in 1972, I have no problem describing myself with the term. Now, others might not share my interpretation....