I think the first time i found an interest in writing was when i was in the first grade and my teacher made us come up with a story, one of those stories that start with once upon a time and end with happily ever after. To be honest i don't remember much about it except that right after that I had a notebook dedicated to writing stories.
I kept this up all the way through the third grade but like in many situations things happened and i eventually stopped writing stories all together. 
I am originally from Mexico, i started school in the United States but it wasn't until the third grade that i started receiving English learning classes. I guess the transition from one language to the other slowed me down in my writing stories.
It wasn't until the eight grade that i had the excitement of writing again i started up slow, my interest was picking up again. The good thing was that through all those years i never lost my love of books, i read hundreds of books both in Spanish and English and even though i wasn't aware of it the constant reading kept me sharp and in touch with my creative side.
But I would give the most credit to me wanting to keep on writing to my high school years, little by little every year i discover how fun and cool it can be to be a writer and have the ability to create worlds.
By my senior year i was in advance English classes and had join the creative writing class after school,  i was writing short stories and finding out what it really means to be a full time writer. Most of my stories were a little similar and i was obsessed with murder mystery and to be honest i took criticism very hard not wanting to except the fact that i don't know every thing and i do need help.
I can honestly say i learned a lot from my mistakes, and now thanks to this site and many years of working hard i am finally able to not only write good stories but also have the ability to take criticism in a good way and grow with every lesson learned.