There have always been arguments showing that free will is an illusion: some based on hard physics, others based on pure logic.
— Ted Chiang
I started submitting stories for publication when I was about 15, but it was many years before I sold anything. I don't make my living writing science fiction, so in that sense, I'm still not a pro.
We don't normally think of it as such, but writing is a technology.
I can't recommend technical writing as a day job for fiction writers because it's going to be hard to write all day and then come home and write fiction.
Probably the most formative experience was reading the 'Foundation' trilogy when I was about twelve years old. That wasn't the first science fiction I had ever read, but it's something that stands out in my memory as having had a big impact on me.
When I was a kid, I figured I would be a physicist when I grew up, and then I would write science fiction on the side. The physicist thing didn't pan out, but writing science fiction on the side did.
The universe began as an enormous breath being held. I am glad that it did... until this great exhalation is finished, my thoughts live on.