How do I know?

I paint every day (almost), I can not imagine my life without it, I successfully sell my art and still do not know what makes someone an Artist. What should separate one from a passionate amateur to professional. Is it $$$ ? Well that would be not right. Would it be the definition of making living by it? But it is again about money. Is it how many hours you spend working at it? But one can spend countless hours (providing financial and social independence ) , It still does not always cut it. Is it a good luck magic ? I probably agree that you can do everything but without Luck or Star or Patron :)) Is it a quality of art? It is also a very subjective opinion in the modern world.