Imagine for a moment if you will that there is a flush-mounted button on the top of your head.  Pressing it would mean instant death, but only you can press it – nobody else can terminate you.  It would be nice and clean, no lingering pain and suffering, the lights would just go out.  You could choose the moment of your demise.

Except you couldn’t bring yourself to press it.  You might run your fingers through your hair over the button and feel a tingle of excitement as you brushed against it, maybe even allow a lazy finger to slide around the rim, but never would you press it.  That would be taboo.  Flirt with the danger, enjoy the risk, but never allow your finger to plunge into the depths, even in a mad fit of pique.

Why?  To most people the prospect is unthinkable, but unless you have a terminal illness and want to die with dignity then staying alive is the ultimate instinct.  If you were in a life-or-death situation, your body would fight to live. If you were drowning you would struggle for breath until the last possible moment.  If you were unconscious, your body would fight for life on your behalf, quite apart from the efforts of the emergency services to resuscitate you.

So imagine those people for whom pressing the button is not only conceivable but a distinct possibility, something to be saved up for one particular day when they feel it is right to do so.  Not just people with depression and other mental illnesses, though they would form a sizeable subset.  Plenty more people for whom this is a rational solution.

And if there was such a button, those who are put off solely by the fact that it can be difficult and painful to kill yourself, the true numbers of people who felt like that would become fully evident.  Many more than you might suspect.