How about the Danny Dunn sci-fi/adventure/mystery series? I was big on those between the ages of maybe 10 and 12, although I think they felt too juvenile for me around when I turned 12. I reread a couple of them a few years ago, though, and maybe my taste wasn't half bad after all. They're pretty good for kid lit.
But by the time I was 13 and started writing my first adventure novel, I had entered a historical fiction kick and wrote something truly awful about a kid my age in 14th century Wales. Despite not knowing a damn thing about either Wales or the historical period in question. 🤣
Months later, I moved on to writing a sci-fi adventure set at the beginning of a generation ship's journey to the stars. Not terribly original. The plot had all the adults dying near the beginning of the trip, leaving the kids to run the show and somehow survive. Being a hopelessly romantic but naive gay boy, there was plenty of first love and brief electric kisses, but no sex beyond that.
The kisses and declarations of undying love were only between boys, natch. And girls were tertiary characters at best, playing gay boys' best friends in stereotypical ways — despite my callow self not being consciously aware the stereotypes existed.
In short, it was awful. Boring. Predictable. Two dimensional. Sexist. I have no idea what happened to my pencil drafts. Probably thrown away in a house move.
But 10 years later, I had a short sci-fi piece published in Omni ... about a generation ship with an all-male crew. So, whaddya know? I guess practice makes perfect, eh? ;-)
Like you, I stopped writing. Life was busy, AIDS happened, I had important work to do, blah blah blah.
Also like you, I eventually discovered online writing, and I've produced what I think is some pretty okay fiction. I even have a literary agent now.
So, given the similar paths, I'm looking forward to seeing you shine on Medium. Keep it coming!