Elpenor was one of Odysseus' comrades, and happened to be the youngest. This was labelled as part of the road of trials for that fact he had to mourn about this, thinking this was his fault. He had to overcome this.
Mythological beliefs gave rise to cathedrals, rituals, traditions, sacrifices, and other parts of life that would not have existed without mythology. Mythology also attributes to the enforcement of laws because the citizens were scared that if they broke laws, they would be punished.