I find it odd as to how can people not be curious of their entirety. Perhaps my thought patterns are simply unconventional but are you not curious as to what the fundamental nature of the Universe is? Of course there is no guarantee that absolute understanding is even possible or how you would even know that you have known everything but the possibility of such an occurrence is enough to desire immortality.
Just think about it, you spend about the first 20 years of your life studying, developing your ideas and your personal philosophy and drive in life, work hard to develop skills, discover interests, strive for your dreams of varying magnitudes, perhaps continue the biological necessity of copulation for the conception of a new generation, go into the working world, climb your way up, possibly engage in intellectual battles with people that you actually relate to, gain fame or watch your ambitions wane in magnitude, retire, enjoy a varying number of years in retirement ( or perhaps lack of purpose for some ) and then die. And with death ends all your work, all the effort, all the ambitions, it all ends. Such a inherent pointlessness in life and you are not even considering immortality to even understand why the hell are we even doing what we are doing? My only conclusion that most people either do not have the ambitions nor mentality to desire immortality or they simply have nothing worth living on past their supposed lifespan. I guess evolution does play a part in this mindset as well. To witness what was science fiction become a reality.To be able to spar intellectually and exchange ideas with the best minds of the future. There is just so much there is to be explored, so much exciting things yet to be experienced that I just cannot see how one can simply not desire immortality. Probably just people who do not have any interest past their daily lives and their social circle.
About the quote, looking at it from a possible scientific explanation of the existence of humans in terms of pure probability. A mistake in that sense isn't inherently positive nor negative. Mistakes often have a negative connotation attached to them but what we consider mistakes are from a human point of view. In the inherent state of the Universe, does mistakes even exist? The concept of morality is also another good one. Is there something in this Universe that can be considered objectively good or evil? I would say no. Good and evil exist only in the human context as an evolutionary measure to promote the survival of the human race. We can't have everyone killing each other as it would be detrimental to our survival. That is why, in my opinion and understanding of scientific concepts as to why killing humans are wrong, the reasoning is similar behind religion. Perhaps we are evolutionary inclined to try to survive at a younger age, but that drive slowly diminishes as we grow older and evolution eradicates the old for the transition the the new. It might be a fundamental law of nature...or there might be a loophole. It's worth a try.
Probably didn't articulate my thoughts as perfectly as I wanted to but I hope I got my point across.