Everyone's story world has an origin. You saw a play that inspired you, watched kids playing in the park, was sick of the story you were reading. Me, I was home sick. That sounds like a silly way to start, but it is the truth.
I, by nature, am a very introverted person. I would spend all my time on my farm and away from people if I could. When I was younger, it was the national forest my father worked in. Nothing is as aspiring as running around in old and second growth trees and pretending to be elves or magical beings or heroes of some sort. I was free in a way most people never will know, stuck in their concrete cities and stuffed in like sardines. But I had a great imagination to go along with my setting.
When I went to college for my biology degree I was now stuck in a city, (Okay, most people might call it a small town, but for me it was huge) and eight hours from my beloved forests. Sure, my future husband was there with me, before we were a thing, and I had awesome friends. But I felt trapped. So I wrote. My father had gifted me with loving fantasy writing and I used it to relieve the stress of being trapped with so many people. At first it was just for my own intake. I wasn't willing to share, but one of our friends was very persuasive and snagged my notebook. He read, smiled, and asked when I got famous would he sign his copy. I laughed, not thinking about ever publishing my writing, but I did keep writing, even after we graduated.
I still don't know if I will ever publish my first go, even if I fix it up, but I'm certainly enjoying the new round of stories to go with my new path in life.
So, my point is, no matter how your story comes into being, remember it fondly when you do publish. It will always be a fun story to tell at those book tours.