Most humans are afraid of dying. I myself don’t want to die… if you offered me a way to become immortal, I would take it. I enjoy life and would like to extend mine as long as I can.
That is the wrong attitude though. We humans only have a 0.1% difference in genetics between even people from different continents. Your own children or parents share far more than that in common with you. This leads me to believe that our selfhood is partially an illusion… others around you basically are you… just different chunks of you with slightly different experiences. We share far, far more in common than we have differences.
When people behave selfishly, you could look at it like many religions do as they are just hurting themselves.
We need to embrace the fact that we are born, we grow during youth, mature into adulthood, then slowly fade with age until we die. Each stage of life is beautiful and interesting in it’s own way. Don’t cling desperately to youth. Don’t fear death.
And most importantly, we need a LOT more mixing of different age groups. The artificial isolation of ages that has developed with the industrial age is very bad for humans of all ages.