It's all about one thing: creative problem-solving to get the story out.
The challenge is about taking things that are infinitely complex and making them simpler and more understandable.
Along the way [Mozart] got married; fathered seven children (two of whom survived into adulthood); performed as a pianist; violinist; and conductor; maintained a successful teaching studio; wrote thousands of letters; traveled widely; attended the theater religiously; played cards, billiards, and bocce; and rode horseback for exercise. Not bad for someone portrayed as a giggling idiot in the movies.
When we hear a Mozart piano concerto today, we're most likely to hear the piano part played on a modern concert grand. In the hands of a professional pianist, such a piano can bury the strings and the winds and hold its own against the brass. But Mozart wasn't composing for a nine-foot-long, thousand-pound piano; he was composing for a five-and-a-half-foot-long, hundred-and-fifty-pound piano built from balsa wood and dental floss.