How do you decide when to call yourself an artist (of any kind)?

Is there a quality standard to call yourself an artist? Or can anyone who writes anything call themselves a writer? Anyone who knocks two sticks on a log can call themselves a musician? Or does it have to be of some quality, such as others recognizing you are an artist? What quality standard is that?

Is there a stick-to-it-tiveness component? You have to practice your art regularly for a certain period of time? How long is that?

Do you only have to think of yourself as an artist to call yourself an artist to other people? Does calling yourself an artist make you an artist?

What do you have to do in order to call yourself an artist and feel like you are telling the truth?