Well, school is just around the corner. My guess is that you won't be spending 100% of your time studying classic novels and poems. (Unless you're a grad student in comparative literature, that is. Or unless you go to an alternative high school with some really odd priorities.) In fact, for years I was only studying classic lit about 10-15% of the time. I entered college intending to go into medicine. Instead, I found my way here.
And I'm not alone in following a professional trajectory like this--certainly not when you start taking heavyweight authors into consideration. Dostoevsky, for instance, was trained in engineering. Chekhov studied medicine. And the list of writers with some legal training includes Gustave Flaubert, Franz Kafka, and Gabriel García Márquez.
But these authors didn't exactly discover literature overnight. More often, these authors had long-term fascinations with reading and storytelling--but weren't ready immerse themselves (and immerse themselves totally) for some time. The same could be said of one of the greatest of writers' writers, Samuel Beckett. During his high school days, Beckett excelled mostly in athletics. He only applied himself to reading and foreign languages during his final years in college. Only then did he set out on the path that would, finally, lead him to world-wide literary fame. Or at least that's one way of looking at it.
Is literature, then, a career that you need to arrive at through trial and error? Do you think there's a reason why authors need so long to figure out their literary callings? I can't think of many writers who pursued writing from youth on, without any deviations whatsoever. Can you?