I wrote my first book when I was 4 or 5. It was a short story about a girl and her cat going on adventures. My mum typed and laminated it for me, and I drew pictures for each page and read it in front of my class, I think I still have it as well. I kind of abandoned writing after that until we had to write descriptive first person paragraphs in year 5, that was when I found that I really liked to write.
Some of my first short stories were unintentional fanfiction, looking back at them. When I started high school (in Aus high school starts in year 7), I decided to come up with my own ideas and write full length novels, I abandoned most of them. I even started to write a collaborative book with one of my friends, before I realised that she didn't have the same level of technique that I did, and it made the work seem patchy.
After a year or 2 of mediocre, wattpad level writing, I found that I actually had a natural talent for syntax (the arrangement of words in a sentence or paragraph, or flow) and had really honed in on the technical side of writing. Around this time is also when my chronic migraines were getting really bad because I had built up an immunity to the medication I was on (which is a common thing for me, I own like fifty different kinds of pain medication), so I wasn't at school most days and didn't have internet at the time, so I would often write to fill the time that I spent on my own. I also really improved my writing speed (I could write a 4/5 page essay in under an hour and a half, and somehow manage an A or A+), and entered a local youth writing competition, in which I came 3rd.
A while later I was also selected by my school to do ICAS English (anyone can participate but my school is a grammar school and likes to be selective. So they pick 3 or 4 people to participate per year level in a specific subject), which I got a Credit for (top 30% of Australia, I really wanted Distinction though).
I like to write in the same way that I like to paint, it's therapeutic for me and helps me get my emotions out. I also really like to plan things, so worldbuilding helps me stay productive and focused. Sorry that was so damn long.