Not a lot of people on this planet could load up a bunch of journals, photographs and recordings from their past into boxes and sell them for $15 million, but that's exactly what just happened with Bob Dylan. And truth be told, $15 million was an absolute steal. He's the most acclaimed songwriter of the 20th century, and his legacy and impact only grows with each passing year. He turns 75 this year, and continues to record and tour at a furious pace. Here are five things you didn't know about him.