The Good Charlotte rocker - who has two children, Harlow, two, and six-month-old Sparrow, with his fashion designer fiancee - appreciates all the love and support Nicole gives him, which in turn makes him a better man.
He said: "I'm the best I've ever been. I have two kids that are my life - they're my entire world. I have an awesome partner who is really supportive; She makes me the best version of myself that I've ever been."
Although he admits becoming a father was shock at first he has always been determined to stand up to his responsibilities.
He told the Los Angeles Times newspaper: "I think you can decide to be the best dad and partner you can be, or you can run from it.
"It's a heavy thing when your life changes. But my kids make me feel good about myself. I'm not really worried about succeeding or failing."
Joel, 31, also admits being a parent has other benefits too as little Harlow can now give him her expert opinion on his new songs.
He revealed: "She says yea or nay when I record a demo. She gives me the honest reaction."