Suicide is inherently selfish and it needs to be. It's about the needs of oneself over the needs of others. I think for someone to get to the point of actually carrying out suicide, and not just contemplating it, one's own pain has to become so unbearable and overwhelming, that the pain that person's suicide might cause to others pales in comparison. I think you just reach a point where you just don't care what it *might* do to others and you become cognizant of the fact that they'll get over it, or, at least, move on with their own lives, in time, after you're gone. Remember, most people aren't suicidal, so the will to live and move on will eventually take over again for them.