Bradley Cooper doesn't think he'd be as successful as he is if he hadn't "changed his life" by giving up alcohol.
The 'Hangover' actor stopped drinking alcohol in his late 20s and thinks the decision he made to transform his life was both "beautiful and unbelievable".
Speaking to Barbara Walters for her '10 Most Fascinating People of 2015' special. he said: "I would never be sitting here with you, no way, no chance, [if I hadn't quit].
"I wouldn't have been able to have access to myself or other people, or even been able to take in other people, if I hadn't changed my life.
"I never would have been able to have the relationships that I do.
"I never would have been able to take care of my father the way I did when he was sick. So many things."
The 40-year-old star was inspired to become an actor after his father, Charles Cooper, showed him 1980 movie 'The Elephant Man' when he was 12 years old.
He recalled: "It floored me. First of all, I was devastated by it. I couldn't stop crying."
Bradley's father tragically passed away in 2011, meaning he never got to see his son play the title role in the stage adaptation on 'The Elephant Man' on both New York's Broadway or London's West End, or 'American Sniper', the movie he starred in which Clint Eastwood directed.
The 'Joy' star said of his success: "I think he wouldn't believe it.
"Thank god he was alive for so many of the successes, but like, the Clint Eastwood thing, he would have really loved. That was one of his heroes."