How often do we reply, when asked what we're doing, "nothing"? Ask kids what they're doing and they'll almost always say "nothing". Is this meaningful?

I was thinking about that, and that only time I ever say "nothing" is when I'm concentrating so hard I don't want to be interrupted by having to explain it to somebody.

I do say "noodling" when I am doing something that I know is completely pointless. (Like say, playing solitaire compulsively when I know I'm tired but can't find the impetus to get up from the computer and go to bed.)