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.
Because most people are not sufficiently employed in themselves they run about loose hungering for employment and satisfy themselves in various supererogatory occupations. The easiest of these occupations which have all to do with making things already made is the making of people: it is called the art of friendship.