During my last year of high school, I took some classes at the local college. One of those classes was calculus, and the plan was to never see it again after that year, instead majoring in creative writing and French.
Then inspiration struck. It does like to strike in the strangest places. I imagined the concepts behind calculus as characters in a story and math as the universe and wondered what kind of story this tale would be. There was one catch: one of the characters, the integral, was still new to me by the end of the semester, and the only way to find out more was to take the dreaded Calculus II. So I did, and that was when I discovered that not only was math cool, but there was a lot out there to be learned about this little mathverse in my head. So I decided to take more math to learn more about this mathverse, and next thing I knew I had a math major and was the token math major in my department.
That creative writing thing? Well, that didn't happen. But I did tack on a French major at the last minute and squeezed in a nonfiction class. As for writing that mathematical story... that hasn't happened yet. I need to do a little more research. Really.