Of all the different art supplies I've used, I think I like pastels and colored pencils the most. Painting is fun but usually involves more setup than I give myself time for.

I think you have a hangup on being 'adultlike' versus 'kidlike'.

No, I see even fingerpainting as a good diversion if the circumstances are right.

Lighten up and don't get so stuck on "once I'm an adult, <list of things> are forbidden to me".