The Wall Street actor admits that when he remembers his hell-raising days of drug-taking, promiscuous sex, and problems in his marriages and with the law, he doesn't recognise himself and wishes he could go back in time and change it.

“I recognise myself by name but not by character," he tells U.K. host Graham Norton on Friday night's show (17Jun16). "I get the shame shivers watching whatever incarnation of who I thought I was in those moments. If I could change any of it I would. It was like there was some measure of possession."

In 2011, at the height of Charlie's wild behaviour, he had a public meltdown and was subsequently dismissed from his lead role in sitcom Two and a Half Men. That same year, he discovered he was HIV-positive, which he only revealed in November 2015. He had previously said he wishes he could blame his 2011 behaviour on that discovery, but it wouldn't be true.

He tells Graham he is now in "a great place" and feels liberated following his HIV announcement.

“It was good to talk about it and what I had been dealing with... It was an opportunity to stop the self-loathing and the ‘why me’ and be part of something genuinely important.”

During his visit to the U.K. this week (beg13Jun16), Charlie confessed his diagnosis has had a massive impact on his sex life, saying at a press event, “Right now, I couldn’t get laid in a women’s prison with a handful of condoms... It doesn’t give me a great opening line: ‘Hey, I’ve got HIV – busy later?'

“It is what it is, and I don’t want to make light of it, but it changes the whole approach on it, because it’s no longer about my interests and my folly, it’s about the other person, it’s about protecting them and just being open and responsible."