I was 13, and a freshman in high school (that would make it, um, 1979). A local community college, Mt. San Antonio College ("Mount Sac" -- funny that I didn't realize at the time how dirty that sounds), announced a science fiction writing contest, to be judged by special guest Ray Bradbury. My mom encouraged me to write something.
A short story. Very short -- maybe 1500-2000 words, tops. A "twist" ending you could see coming a mile away.
And I won. At this point -- 33 years later -- I don't remember whether I won the "under-18" group, or came in 3rd overall; I know I didn't win the whole contest, but I did well enough to meet Mr. Bradbury. My most vivid memory of the event is walking alongside him, outside, looking up at him and grinning like a fool.
A few days later, my English teacher offered to read the story to the class. That twist ending? Wasn't so obvious to other 13 & 14 year olds. My other vivid memory of this moment in time is hearing Mr. Brechbiel (the teacher) finish the story, then a beat of silence, then one of the other kids saying "Ooooh!" in realization of what the ending meant.
That second, that sound, that excitement of witnessing the reaction... it told me, with no uncertainty, that words have power. That what I write can make people think, affect their emotions, change their ideas. That "Ooooh!" put me on the path to where I am today.
And Ray Bradbury, by giving a bit of attention to a 13 year old me, pointed me in that direction.
Thanks, Ray. Rest in peace.