LOS ANGELES—To the extent that he ever really went away, Charlie Sheen is back.

He knows that you know that he knows that you know all about the sensational circumstances of his departure from “Two and a Half Men,” and the first words he speaks in “Anger Management,” the FX sitcom premiering today that will restore, confirm or destroy his reputation go straight to that point.

“You can’t fire me, I quit. You can’t replace me with some other guy; it won’t be the same. You may think I’m losing but I’m not — anyway, you get the idea.”