I began my writing career as a child, writing short stories that mirrored what I was reading. SF phase? I wrote SF stories, etc. I didn't write just to have fun, I tried to get my work published. That failed, but hey, getting a rejection slip as a child was kind of cool.
I have written elsewhere that I am the author of the world's shortest short story. It's true. Go ahead, think of the shortest story possible. How about: