I have no idea why I started liking horses, my parents had no interest whatsoever, despite both of them being born/raised on farms that had working horses, or a pony and trap ...
I did find out a few years ago that my grandfather had been in the Cavalry in WWII
I can always remember liking ponies and wanted one as soon as I was able to ask, but my parents weren't interested and would get really angry at me for asking.
When I was 12 a riding school opened in walking distance of our house, so I started having lessons. The woman who owned the place didn't like me and would put me on the slow, old, dopey ponies and it was over a year before I ever managed to canter, and another year before I learned to jump.
I saved up all my money and when I was 18 I bought myself a pony, I had her for nearly two years before being offered a job as a groom at a showing yard, and my parents made me sell the pony. The job offer was removed (apparently a few days after the woman offered me the job - after a lengthy interview process because she wanted the right person for the job) a boy wandered into the yard and asked "any jobs going?" so she hired him on the spot!

(as a PS to that, she phoned me a month later pretending not to know who I was and asked if I was looking for a job as a groom in a showing yard etc, apparently she'd hired a young man who'd left! Hah! I didn't take the job, I thought she sounded a bit 'crazy' TBH) andyhoos there was me with no job, no pony and no money to buy her back as I'd spend half the money I got for her on new gear I'd need when I left home
Over the next 25 years I had lessons sporadically, three years ago I started riding again after a 4 year break due to a [no horse related] back injury, and a year later I bought myself a new horse