In a cold cultural calculus, stars often are rewarded or punished based on how far they deviate from our expectations.
After Charlie Sheen embarrassed both CBS and Warner Brothers with his drinking, drugs, women and attacks on studio executives, the key question was posed not by CNN talk host Piers Morgan, but by Sheen himself: Why didn't they replace me sooner?
The answer, of course, is because he made a lot of money for the network and studio behind "Two and a Half Men."
The revenue rolled in because a lot of people tuned in to watch Sheen, despite his history of bad behavior.
Or was it because of it?
After all, the boundaries were blurred between the real-life and TV good-time Charlies.
Like Sheen, his "Two and a Half Men" alter-ego, Charlie Harper -- boozing, carousing, callous -- is irresponsible. Yet he was irresistible to the average audience of 14.5 million that made the show the small screen's biggest hit sitcom.
Sheen reflects the cold cultural calculus of today's pop-star marketplace: Performers are rewarded or punished based on how far they deviate from our expectation sets.
What would have been a career-breaker in previous generations is now a career-maker for some stars.
"In some cases we not only will tolerate our celebrities behaving badly, but we expect them to," said Robert Thompson, director of the Bleier Center for Television and Popular Culture at Syracuse University.
Sheen was embraced in part because his on- and off-screen falls from grace were concurrent.
In the movies, he went from the moral grunt fighting immorality in Vietnam in "Platoon" to progressively darker characters: Bud Fox, who traded stock, and his soul, in "Wall Street"; Happy Felsch, in the sad story of baseball corruption, "Eight Men Out"; "Major League's" Ricky Vaughn -- better known as "Wild Thing," a nickname that was apt for Sheen's off-screen tabloid troubles.
Tolerance of Sheen stands in stark contrast to another star from his generation: Winona Ryder. She was nominated for Best Supporting Actress Oscars for roles in "Little Women" and "The Age of Innocence," but the guilty verdict in her shoplifting trial stopped her career cold.
Now she's back, most recently cast as a washed-up, diva ballerina in "Black Swan."
Mel Gibson, too, is trying for an art-imitates-life comeback. In "The Beaver," which premieres at this month's South by Southwest Festival, Gibson's character tries to resurrect a wrecked life.
In real life, of course, Gibson's marriage and movie career collapsed after misogynistic and anti-Semitic antics made him toxic in Hollywood.
It's not just stars of a certain age who are trying to negotiate a ruthless marketplace. Lindsay Lohan, who is now more famous for being infamous, was once a shooting star due to remakes of Disney's "Freaky Friday" and "The Parent Trap."
But just as with two other Disney teen queens, Britney Spears and Miley Cyrus, it's a tough transition for the public when cute kids go from PG-rated entertainment to R-rated behavior.
Yet it was X-rated sex tapes that thrust Paris Hilton and Kim Kardashian into the limelight. But because they were never sold as family-friendly, both became big reality TV stars.
Sometimes it's not being wild, but weird, that gets punished in pop culture.
Tom Cruise became a big star after dancing in his underwear in "Risky Business." But when he danced on Oprah's couch, he became a pop-culture punch line.
Paramount Pictures probably didn't laugh, however: In 2000, Cruise's "Mission: Impossible II" made $215.4 million at the box office.
The summer after his couch dance, "Mission: Impossible III" made only $134 million.
This pattern isn't just a TV and film phenomenon. Chris Brown was on his way to music's Grammy Awards -- and superstardom -- when he assaulted his then-girlfriend, pop star Rihanna.
His career careened, leading him to lash out on Twitter that his comeback album was being boycotted by retailers. Not so, they claimed: It's just hard to sell a soul singer when the public thinks the singer lost his.
Eminem, conversely, has had his brushes with the law. But by playing them to enhance his street cred, he became a top-selling artist, and just got the ultimate acceptance: Not one, but two Super Bowl commercials.
The Philadelphia Eagles' Michael Vick didn't play in this year's big game. But if he did, his comeback story from convicted dogfighter to convincingly redeemed quarterback would have been the stuff of an NFL Network -- or even Lifetime --made-for-TV movie.
Meanwhile, Tiger Woods, who by his own admission acted immorally -- but unlike Vick, not illegally -- has been abandoned by most sponsors and many fans. The difference?
Tiger was sold as a symbol of corporate mastery -- "Go on, be a Tiger," implored Accenture in its ads. No corporation urged us to be a Michael Vick, who instead was just marketed as a tough guy in a brutal league.
Pop culture itself seems to be a brutal league.
What's changed is how we view self-destruction.
Last week, we were watching. A "Two and a Half Men" rerun beat original episodes of rival shows Monday.
The rerun aired at the same time that Sheen's live interview set a ratings record for Piers Morgan's show. And 9.3 million viewers became voyeurs as Sheen tried to sort out his sordid lifestyle on ABC's "20/20."
Given the interest, inevitably there will be talk about Sheen's comeback. But any on-screen recovery will probably depend on recovery programs he mocked in multiple interviews.
For his and his family's sake, let's hope he realizes that unlike Charlie Harper, Charlie Sheen's lifestyle is far more drama than sitcom.