When I turned 73, a dear friend's dare to "Prove it," became a rude awakening. For years, I'd smugly bragged that writing classes were a waste of time, that instinct was everything, if I shopped the drawer full of short stories I'd written over the years as a hobby, they'd immediately find homes in various magazines despite the fact that I'd never taken a writing course.
Well, I've been submitting stories for two years now and I'm still unpublished. After frustrating upside-down, left-to-right, inside-out revision after revision went unsold, I finally got the message. Since I've never taken the courses, make friends with those who have.