I just got back from a literary conference with a mixed group of attendees, everything from fans of certain authors, to dabblers, to serious writers. And of course, there were the usual mix of professional writers, agents, editors, marketers, etc., invited to present or perform some other professional duty.
One of the first things you do when meeting someone at a conference is to ascertain in what capacity they're attending the conference, and so I frequently ask, "So. . .are you a writer?"
Often people will say yes (if they are), and then immediately water that down with caveats. "Well, an aspiring writer, anyway," or maybe, "I want to be. I hope to be some day." Or worst of all, they give a nervous chuckle and say, "Not a real writer, but I'm interesting in learning about it." Once they find out I'm there as a guest and not a paid attendee, these caveats multiply.
Regardless of the answer, I usually ask what they're working on now. Some of this is polite conversation, but mostly it's to measure the person against my own guidelines, to divide the dabblers from the serious writers.
This next part is important. A dabbler isn't an amateur, and a serious writer isn't a professional. That is not the dividing line at all. A dabbler is someone who doesn't write, and a serious writer is someone who produces words in serious quantities and with serious intent.
That's all. Nothing else can be controlled, not sales, awards, recognition, not even a simple response to a crummy query letter that says yes or no. Only the words that come out of your mind and find their way to paper or screen, and then get shoved out into the world to either make their way or not.
So if you write, you're a writer. Lift your chin, barrel your chest, and own it. Storyteller is the earliest profession (with apologies to the usual claimant), and remains the glue that holds human civilization together. You're not a brain surgeon or a rocket scientist; you're something more important. A writer.