Article continues below advertisementCharlie Sheen is looking back on his checkered past as he turns 60 years old on September 3 - and how he remains clean to this day. "I have more days behind me than in front of me, and that's fine," he told a media outlet. "But I'm feeling pretty good! Most guys my age, they usually have a bad back or knees. Somehow I dodged that."Article continues below advertisementCharlie Sheen Was a Tabloid FixtureSource: MEGACharlie Sheen is gearing up to release his memoir on September 9.