Consider this: Something within Sam would make him the best violin player ever to walk the earth.
Unfortunately, Sam has grown up in the slums of Chad and never even hears a violin, much less gets the chance to practice or own one. OR perhaps Sam has all the skills and brains to be a great violinist, but he has stage fright or he loses a hand in an accident or some other issue that keeps him from actually showing this talent to the world.
Then I wonder how that plays out in my classroom. Bad test takers? Less-than-ideal backgrounds? Other handicaps physical or mental that might keep a kid from doing her best?