Pitt's positive outlook seems to be a result of spending more time with his kids, a source tells People.
The actor initially agreed to weekly supervised visits with his and Angelina Jolie's six kids -- Maddox, 15, Pax, 13, Zahara, 12, Shiloh, 10, and twins Vivienne and Knox, 8 -- after the couple's split. However, People's source says that things have since cooled down and Pitt "can spend more time with them."
On Jan. 9, Pitt and Jolie released a joint statement revealing that they were working with a private judge on their divorce case, and stated that they were "committed to act as a united front" moving forward.
"He seems much happier," People's source continued. "He has missed his kids terribly. The kids are his whole world. It's all he cares about."