I was consulting with a doctor recently, and in the course of the conversation, he asked what I do. I told him that mainly, I was a mother, but that I was also a violinist. Later on in the meeting, he referred to music as my "hobby," and then talked about how he wished he had more time for his hobbies.
Had I been a lawyer, who had put my career on hold to have a family, occasionally offering legal advice now and again, would anyone refer to that as a "hobby?" I dare say, they would not!
I guess that is one of the perils of doing something you love, rather than something that makes money. To be fair, no one has to certify in violin playing to perform--and there are certainly a lot of fine amateur musicians who really do play just for fun. In a way, I wish I could say that I play "for fun," but I really don't have fun unless I'm seriously playing.
So, I bristle when someone asks me if I'm "still playing the ol' violin," as if it were something I could ever not do. As much as I hate to be defined by others as a violinist, as if there were no other human qualities about me, I AM a violinist--and it's no hobby!