My first inkling that I could become a writer happened in the 6th Grade when my teacher accused me of plagiarizing a story I had written about sailing a yawl around Cape Horn in a storm. I knew that I had created it on my own. My Dad went to bat for me where he relayed that we had sailed various classes of my Uncle's boats on Sunday and that I had learned nautical terms. He asked the teacher to name the work I had taken it from. He could not.
The teacher failed me because he was certain that I copied the work.
I took this as an affirmation that I was a writer. For 20 years I was a bad writer slugging it out. Since then I have become a better writer, not great, but better.
Now, I can't stop...writing. I love the sound of words in my head and those that tumble 'cross my tongue.
Advice - write when there's nothing to write about. Write about boredom, for example. Write until you find your voice in fiction or non-fiction and read everything.