The Curious Case of Benjamin Button star - who turns 45 on December 18 -is looking forward to ageing because he thinks older people are more intelligent.
He said: "I like the wisdom that comes with age. I wouldn't trade it for youth any day."
In the new movie, Brad plays a man who is born elderly and ages backwards. The actor revealed he enjoyed the challenge of playing an old man, but hated the length of time it took to get ready.
He said: "My mornings started very early - getting up at 3 am and sitting in the chair for four or five hours."
Brad, who sports a moustache in upcoming war movie Inglourious Basterds and recently said he wants facial hair to be fashionable again, also joked his friend George Clooney was copying his style.
He added to US TV show Extra: "George is a handsome dude, what can I tell you? I can't get this guy out of my slipstream. I get a moustache. He gets a moustache."
George wasn't the only Hollywood star Brad praised - he also had kind words for Tom Cruise, his co-star on 1994 movie Interview with the Vampire. Brad said: "Of course I'd work with Tom again. He's a friend of mine. He's a strong one, that guy. I loved what he did in Tropic Thunder. The ending is hilarious."