I always wonder whether to get closer to 'nothingness' you need more or less capacity to think. I would guess nothing is exactly what first comes to mind, no thought required. Death, blackness, absence.. FEAR. We spend our lives trying to become more everything - less nothing - because we fear nothing. The more we fear, the less we become, we fear 'less', so we fear ourselves. Confusing I know... what's even more confusing is : Less is more.
There is a book from the 70's called "on the the road to damascus" or something very close to that...it is applicable to this thread.