“Two and a Half Men” star Jon Cryer says he was genuinely surprised by Charlie Sheen's recent headline-making behavior and antics. “It's as much a mystery to me as to everybody, I think,” he said on a recent show on “The Late Show With David Letterman.” “My favorite moment was when I got a text actually, from someone, I don't know who it was, saying, 'Charlie Sheen just called Thomas Jefferson a dick.' I said, 'I think things are getting out of hand’,” Jon joked.