Charlie Sheen, the uber-Hollywood bad boy, just did something no one saw coming: he publicly apologized for being, in his own words, an "a**hole-5,000" to Dax Shepard. And it was over something that happened more than 20 years ago! Oh, and get this: Dax didn't even remember it! The unexpected mea culpa went down on the latest episode of Dax's Armchair Expert podcast, where Charlie popped in as part of the press blitz for his new memoir The Book of Sheen, as well as his new documentary aka Charlie Sheen.