At 35 I'm definitely starting to feel more like a grown-up than I ever have. There's nothing in my life that is childish or whimsical. Having fun is fantastic and I never want to lose a sense of that - and also I think you have to have that to put into your work or else it's going to feel stiff.
When you're young you're always wondering when you're actually going to feel like a grownup. And I think you probably fear it in a sense too. There's a danger to feeling like an adult... like this whimsical kid in you is going to die or something. And then all of a sudden one day you kind of feel like an adult and it's really nice.
Loving a child doesn't mean giving in to all his whims to love him is to bring out the best in him to teach him to love what is difficult.