Once I was a writer in the sense that I wrote sometimes.
Now, I am a writer in the sense that I depend on it. Like exercise, or sleep: it is a part of my day. My head fills with words and sentences to write and each day, I empty my head: scribble it down or type it out.
It was harder before, when I cared too much about structure and organization. I would keep things in my head too long, until I could be at my computer, put it in the proper Word doc. Or until I had my proper journal, which I have some inexplicable system as to what warrants entry. My thoughts would vanish there, into some dark corner of my brain, never to be found again.
But now, I have a "fuck it" notebook that I put anything and everything in. A sentence to use in a new piece, a revision idea for a current piece, a journal entry, a poem, a check list. It's a fucking mess. But it empties me out so I can fill back up with other thoughts to write down. I am creating content that I might use one day, might not. But it exists, somewhere outside my mind now, somewhere discoverable, which is what writing is, basically.
Writing is putting your thoughts somewhere discoverable: somewhere that someone one day will find it, maybe even appreciate it, maybe even tell you.