On Christmas day in 2004, Dame Ellen MacArthur found herself racing a storm on the Southern Ocean, 2,000 miles from the nearest town. The closest land mass was Antarctica and the closest people were manning the European Space Station above her. The winds were 80 knots, and the waves were already 40 to 50 feet high. When MacArthur finished her solo trip around the world in record time, she had a revelation that made her give up sailing and take on a different cause. Watch this TED talk to find out what she learned.