"It really changes your perspective on the world," Pitt, 42, said during a Today show interview aired Monday morning. "You know, I've had my day. I made some films, and I've really had a very fortunate life, and it's time for me to share that a little bit."
Admitting that he shares his partner Angelina Jolie's belief in contributing to humanitarian causes, Pitt also credited the couple's kids – Maddox, 4, Zahara, 1, and 6-week-old daughter Shiloh – with the shift in his attitude.
Having children, he said, "completely changes your perspective and certainly takes the focus off yourself, which I'm really grateful for." Chuckling, he added: "I'm so tired of thinking about myself. I'm sick of myself."
Of parenting, he said, "You feel you want to be there and not miss out on anything. It's a true joy (and) a very profound love. You can write a book, you can make a movie, you can paint a painting, but having kids is the most extraordinary thing I've ever taken on."
Pitt's interview took place during his weekend visit to New Orleans, where he met with community leaders to lend his support to a Global Green effort for affordable, eco-friendly housing.
"It's shocking," Pitt said of the lack of progress in the hurricane-ravaged area. "Driving by houses in the Ninth Ward ... it is just devastating."
Pitt's participation includes his sponsorship and $100,000 investment in an architectural competition to design an eco-friendly 12-unit apartment complex. (The contest drew 3,000 applicants from around the globe and has now been narrowed down to six finalists.)
"My goal," Pitt said on Today, "is to see something tangible, to see something built that can become an example, a template ... a flagship for other people who are facing rebuilding."