You should write because you love the shape of stories and sentences and the creation of different words on a page. Writing comes from reading, and reading is the finest teacher of how to write.
“If he is conscientious, his preliminary work consists precisely of moving backward from the effect to the cause. Starting from this end result — the viewer’s emotional response — he looks for the combinations that will be most effective in its creation. It’s a path taken in reverse, a step-by-step retreat, full of choices, puzzles, redactions, interpolations, that arrives inevitably at the origins of the composition: that is, at composition itself.”
Robert Bresson