What do you make of the several people on this forum who claim to have done it?
well, as i said - "i also notice that at times, a state of quiet mind can be present"
i think similarly to kourosh; it can be managed to some (varying) degree, using techniques like meditation, with the intent of directing it for useful purpose, as a sort of mindfulness 'tool', (if you will) - as opposed to it yammering on unbridled to the extent that it disturbs or overwhelms.
i'm a musician, and for me, playing music is a form of meditation; the moments while i'm practicing/performing are the few moments when it's completely silent - i attribute this to intense focused concentration within a particular organizational structure. (meditation-like). Maybe the 'runner's high' we often hear about is something similar (not sure, that is just a guess, as i'm not a runner)
so i think that although it can be managed to some degree and/or channeled to a mindful purpose, and indeed achieve moments
of quiet mind, overall it can't be eradicated or shut up completely - and i don't attempt to do so, cause that's not the goal. my way of being is to accept it as something normal and natural, part of self, not 'outside of self', and work with it -- instead of thinking of it as something 'bad' that i must fight against, to 'get rid of'. this approach in and of itself, lessens the knee-jerk 'upset' reaction when i notice it occurring.