He said: "I didn't lose any friends because of it because it doesn't bother me watching my mates getting drunk when we go out.
"But it was the best decision I ever made in my whole life. Now I go home at 1am instead of four in the morning."
As well as quitting alcohol and his heavy smoking habit, 34-year-old Colin – who has sons James, seven, and Henry, 14 months, from previous relationships – is currently working hard to get fit for his role in the ‘Total Recall’ remake, in which he will take on the lead character of Douglas Quaid, who was originally made famous by Arnold Schwarzenegger.
He said: "I've got this hairy Croatian boxing coach who tortures me every day.
"I need big muscles for this new movie. He's killing me with his drills."
Colin, who has been sober for over two years, has previously insisted he doesn’t regret any of his former wild behavior.
He said earlier this year: "The ins and outs of what I've been through, even when it comes to rehab, is not a sad story.
"None of it is a sad story. I had a great time and some amazing memories and lots of good stuff that I've forgotten."