Like many have said preparing planning and getting everything set was a breeze if not a coping mechanism. But when it comes down to actually pulling the trigger, there is this hesitancy, this terror. Suicideology his largely debunked the idea of Si because there are nine scientific definitions for instinct and survival is not recognized as anything more than a theological idea, human beings are not goal oriented towards survival, we're goal oriented towards the propagation of our genetic material. SI is more a mixture of phobias and fears of the unknown, uncertainties in the process and fear of consequences should things go wrong. The thought of one's own Extinction can be paralyzing. To actually cross over and go through with it all requires either a moment of impulse or you have to chemically induce an altered mental status such as with benzos and alcohol that will enable you to more easily engage in something reckless that you would not otherwise do sober. That or an altered mental status from some negative stimuli that'll throw you over the edge that you have to catch at the right time with the lethal means on hand and when you're not thinking clearly. Once you engage the brain, you're fucked.