Here's the thing about nothing - it can actually be nothing, or it can be very much something.
Me: Kids, what are you doing?
Kids: (giggling while answering in unison) Nothing...
Further investigation reveals complete mayhem in their bedrooms...blankets and sheets off the mattress, pillows strewn about, and tiny little flushed faces indicating that there has been some significant bed jumping going on. One can practically hear the mattress groaning in pain.
Or this one:
Me: Whatcha doin'?
Robert: (warily) Uh, nothing?
Robert: (after a short pause) Why?
Me: No reason.
Robert: (radiating waves of doubt) Ooo-kay
Me: I love you.
Robert: No, really what do you want? (you can almost hear him thinking - 'please don't want to rearrange the furniture.')
Nothing. There's something in it for everyone.