the other day, a few guys were riding their bikes in the andes. As they rode the singletrack, they noticed somebody else was riding the trail. they got closer, and they noticed it was a girl, 12 or 13 years old.
she is a local girl, whose family lives from subsistance farming and herding in the andes. she says she rides her bike often, but living so far from the city (3-4hr walk) she does not have access, nor money for spares. still, she likes to ride her bike, and has kept riding the bike until, literally, the tires fell off.
full story here: http://www.ridemonkey.com/forums/f2/girl-tireless-bike-249750/