Just came across this
http://www.youtube.com/watch?v=_xFLf3HoDtQ
Every woman I'm close to - family, GFs, friends - has witnessed me sitting down, looking up or far away and appearing to be in deep thoughts. However, that's just me thinking of nothing and giving my mind a rest.
Yet "nothing" is never a good enough answer for them!
I reckon the more a man does that around someone, the more comfortable he is with that person's presence.
It's simply an expression of the Man Cave - but instead of a physical cave, it's a virtual cave which our (men's) mind escapes to.
One of my ex, who's studying to become a doctor that screws with people's heads (heaven saves them, she's nuts), said that it's impossible for women to think of nothing.
Can you girls think of nothing?