K. G. It's all a twisted, sprawling web of people living for the sake of one another, with none of it actually going anywhere. A self-contained tangle of obligations based on privation and fear of loss, not on actually accomplishing anything. Like the guy said, we only exist to create more people whose purpose is to create more people, ad nauseum. It's absurd. Even if we never go extinct (highly doubtful), it still doesn't amount to anything. Just billions if not trillions of souls ground into dust for the next batch. All "accomplishments" are merely attempts to improve the living conditions of the next generation, but the latter has no reason to exist. In a hundred thousand years, what state of being can mankind possibly occupy that would render the previous milennia of suffering and bloodshed justified? If we ever achieve some god-like utopia in the stars, it will be built on the countless bones of those who are no longer around to enjoy its fruits, by those whose non-existence would deprive the universe of nothing anyway. Maybe I just lack imagination, but in what possible world could humanity's continued existence have any real meaning? The Buddhists are right. The problem isn't the shittiness of this existence, this contingent place in time and space that can conceivably be different—it is the very concept of subjective, conscious, finite existence itself. There is no place for meaning, for purpose, for lasting achievement within this reality.
So don't blame this guy's sister for her selfishness; it's all she can do, the poor wretch. Even if the value of the relationship is completely lopsided. Even if she can't conceive of the fact that no matter how bad her grief gets should her brother die, she will likely never be driven to suicide. That asking her chronically suicidal brother to hold out for her sake is like barging into an ER and demanding to be treated for a broken arm when there's a guy ahead of you who's having a stroke. She won't get it. They never do. And if they do get it, they don't care. At least not enough to get through to them. I know this from experience. If you don't immediately and intuitively see why guilting people (whom you don't depend on for survival yourself) into staying alive is sick and wrong, I doubt such understanding can be instilled, except maybe through some traumatic personal event.