21Andrew Jackson
Andrew Jackson participated in the American Revolution informally at the age of 13 as a courier, survived being captured by the British, and was the only member of his family to survive the revolution, becoming an orphan at the age of 14.
22Kurt Cobain
14-year-old Kurt Cobain announced to a schoolmate that he'd be a superstar musician, get rich and famous, kill himself and go out in a blaze of glory like Jimi Hendrix.