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!
Hold my breath going through tunnels. This really backfired when I was on vacation in Hong Kong and went through a hella long tunnel. Did not know what I was signing up for.