The most significant piece of advice my father gave me early on about acting was, don't get caught acting. Really believe in what you're doing and then commit to it. Even if it feels uncomfortable, even if you feel that you're gonna look like an ass. It's all acting, but find the truth in a moment as opposed to just pretending you have and rather than trying to act your way out of it.
When I was younger, my whole sense of self-worth was based on whether or not I was working, which was awful. And I had a baby at 20 years old, so it wasn't just about me. At around the age of 30 there was a stretch where I wasn't working - certainly not on anything I liked, anyway - and I started to do other things.
I'm not that complicated as an actor. I have a formula in which I work, yeah. But not like Sean Penn does. Sean is one of the few actors I know who can work like that, actually becoming the character he is playing, and get consistent results. I don't believe you can ever be someone else. You manifest different levels of your own personality to come up with a character.
I've always traveled with a picture of my daughter from 1989, her kindergarten school picture, that has 'I love you, Daddy' written on it. She's always made fun of me because I never changed that picture out. It's like my resistance to her getting older. It was the first thing she'd ever written to me and it means the world to me.