From Winona to Angus, now we know how long rehabilitation takes Once it was simple. You did something bad, you were found out, and that was it. You either clamped a 12-bore to your head or emigrated to Australia. But after the 1960s, British society came over all magnanimous. When John Profumo resigned as MP after sleeping with a prostitute, lying to Parliament and toppling the Conservative government, he worked as a volunteer cleaning lavatories in an East End charity hall - and in 1975 he was given the CBE, perhaps for services to hair-shirt wearing. Shame in sufficient quantity brought rehabilitation. High-profile Americans don't do shame. They do confession. When Winona Ryder was caught shoplifting clothes, she went on TV to explain how she suffered from anxiety and depression. When Robert Downey Jnr was arrested for drugs and gun possession, he discussed his addictive personality on Oprah Winfrey's show. And they didn't need to wait for the public to forgive them; they had to wait until they were pronounced insurable by film companies. These reflections are prompted by the case of Angus Deayton, a man whose career has been shadowed by scandal and whose last 10 years have been a curious journey of enforced rehabilitation. In 2002, Deayton was forced to resign from Have I Got News For You after allegations in the News of the World of coke-snorting and three-in-a-bed malarkey. Deayton never displayed remorse, nor presented himself as ill. He simply bided his time, while the BBC tied itself in knots wondering what to do with him. They knew most of his audience wanted him back in the show, but had to pretend to be ashamed on his behalf. There followed a cat-and-mouse game in which the Corporation proffered their former star to small, try-out audiences, like a lion-tamer offering little snacks to the lion to see if it would eat them or devour him instead. After a year, he was allowed to be a guest on a radio comedy show. After two years, he was cast in a TV comedy that went out on the wastelands of BBC Three. After four years, the Beeb let him present a TV charity show. After another decent interval, he was finally back on BBC1 in 2007 fronting Would I Lie To You? until he got into trouble again for making rude jokes about Jimmy Savile. Yesterday, the BBC announced Deayton's coming back to the fold in Waterloo Road, the mainstream drama set in a dysfunctional school. It took Profumo 12 years to have his transgression officially forgiven. It took Deayton five. And guess what? It took Winona Ryder the same period to get back into movies (with A Scanner Darkly in 2006.) And Robert Downey Jnr had to wait five years before the insurers would trust him again. So it's five years. That's the decent interval now. Just before midday yesterday, seated on a white throne, with awful majesty the Pope extended a prehensile forefinger to a papal iPad and sent his first tweet. His account @pontifex has already got 840,000 followers, most of whom immediately leapt into action to complain about abusive priests, ask if he likes Justin Beiber or suggest he gets in touch with @DalaiLama. This is not, I fear, what the great man's advisers had in mind. He hoped to communicate with millions longing for spiritual refreshment. What the millions really long for is to be hilariously abusive enough to be blocked on Twitter by the Supreme Pontiff. How cool is that? Twitter@johnhenrywalsh