The `Real Steel` actor and his wife Deborra-Lee Furness were devastated when they were told they couldn`t have kids naturally but now they know it was fate to welcome Oscar, 11, and six-year-old Ava into their lives.
He told Australia`s Herald Sun newspaper: "It was painful. It`s not easy. You put a lot of time and effort into it, so it`s emotional. I think any parent can relate - trying to have children is wonderful and when you feel as though that`s not going to happen, there`s a certain anxiety that goes with it.
"We thought we`d have a kid or two biologically and then adopt. But when we decided we`d had enough of IVF, we went ahead with adoption.
"From the moment we started the adoption process, all the anxiety went away. I don`t think of them as adopted - they`re our children. Deb and I are believers in I suppose you could call it destiny. We feel things happened the way they are meant to. Obviously, biologically wasn`t the way we were meant to have children."
Although he admits family life isn`t always easy, he knows he and Deborra made the right choices.
He said: "Now, as we go through life together, sure there are challenges, but everyone`s in the right place with the right people. It sounds airy-fairy, but it`s something we feel very deeply."