What is a fun childish thing you still do as an adult?
For me, it's sticking my hand out of the window of a moving car. Whether I'm driving or not, I love having the windows down and waving my hand in the wind. I've loved it since I was a child and I'll never stop doing it!
This is more of a highschool childish, but occasionally I like to smoke weed and stay up till 3am playing video games. Then call in sick for work the next day of course