Is this another of your sneaky tricks? :P I would say you can't *think* of nothing as such, as it would be a double negative? If you are thinking of nothing, you are, by definition, thinking of *something*?
Did I get it right? Prize for me? Or do i get to stand in the Dunce's corner?
I can often let my mind go blank as in I am not actively thinking of anything.. perhaps that's what you meant?
It's how I get to sleep.. I have to allow my mind to stop thinking.. I've had to train myself to do it.. or I get a million thoughts keeping me awake.. with me I allow pictures to come into my mind.. almost pre-dreaming state... i am not allowed to comment, mentally on the pictures OR feel anything about them.. I have to observe them as if I am a bystander...
I just learned it.. as I used to have a lot of problems sleeping... it doesn't work 100% of the time, if I am very, very wound up then thoughts will still pop in and override the pictures.. but it works 98% of the time.
If you're thinking then you must be thinking about something, even if the thing you're thinking about is "nothing". I have, occasionally and for a very short time, allowed my mind to go completely blank so that there is no conscious thought. (Usually happens when Mrs Didge wants me to get off the Internet and go cut the grass.)
as long as thought is happening one cannot think of nothing. As soon as thought is gone, and ego is gone one can be in nothingness better called oneness.
Benedict Arnold 