I've been reading a book on and off for months called "Writing Motherhood." I don't remember the author's name and I'm pretty sure it's a relatively old book. Though I am just not getting into the meat of the book, I noticed a really good point in the book very early on in its pages.
The author was talking about being asked to teach a writing class before she really felt qualified to teach it as a writer. She went ahead and taught it anyway and learned that she became a teacher through teaching. Her students, in essence, taught her to teach.
The idea I got from that was that the only way to really become a writer is to write. You can take all of the classes you want. You can learn the craft. You can read. But if you really want to be a writer, the only real way to do it is to do it.
Let's use being a parent as an example. Or more specifically, a mother. I've been a mom for nearly 5 years. Before I was a mom, sure, I wondered how I would do some things, but overall I had no idea what I was doing and I openly admitted that. I had never changed a diaper...fed a baby...rocked a baby...the list went on and on. I had no real clue what it took to be a mom. And yet I had my daughter in 2009 and was thrown into the whole motherhood realm face first. She taught me how to be a mother by allowing me to do it.
Since 2009, I've learned a lot about being a mom. Things with my second daughter went much more smoothly in the early days of her life because I knew what I was doing from trial and error the first time around. I became a mom because I had my daughters. There was no other way.
The same can be said about writing. You can read about writing and learn everything you possibly want to know about the issue, but it doesn't make you a writer. The only way to write is to write. And once you start writing, then you can really hone your craft and learn and fine tune. Do the things you do in advance help? Sure! But you aren't going to know what will work and what won't work until you try it.
So if you want to be a writer, quite talking about it. You want to be a writer but... There are no excuses. If you want to be a writer...write. The rest will fall into place as you are doing it.