Brad Pitt and Cate Blanchett

What a difference four years can make! Since Brad last sat on Oprah's couch in 2004, he has become a proud father of six children. Will there be more? "Probably," Brad says. "It's the thing I'm most proud of. It's the greatest endeavor we've ever taken and the most interesting, most fulfilling, most rewarding thing I have ever experienced, and why should I stop?"

Along with the joys of fatherhood, Brad says he's learned to develop a thick skin. "I'm impervious to poo, snot, urine, vomit," he says. "You can't get me. You cannot break me down."