>>Sounds like the perfect excuse for selfishness. If your life is all there is then why worry about anyone else?<<

Believe it or not but atheist also have a desire to procreate and a love for family and close kin. The most selfless act that can be done is give ones life up for another, altruism. Richard Dawkins explained altruism with a modification of Darwin’s natural selection theory. Dawkins argues that natural doesn’t take place at the level of the individual, as Darwin had proposed, but operates at the level of the gene. We put our lives at a slight risk to save a close relative because there is a good chance this act will increase our own gene copy number. What looks like a selfless act of an individual is actually a selfish act of our genes. So, selfishness isn’t all bad.

>>"After they die they die."

You know what they say "born once die twice" (your words) "born twice die once".<<

What that author is saying is after they die they stay died.