I remember Joseph Campbell saying something like - A myth is something that never happened, but is always going on. Richard Rohr put it this way:
Remember, myth does not mean “not true,” which is the common misunderstanding; it actually refers to things that are always true!
Most of the great truths are taught in myth form. I think of the stories as parables, stories with layers of meaning. They speak to us with many meanings, if we have ears to hear.
For example, let us think of the prodigal son story that Jesus told. The main characters are the older son, the younger son and the father, with some supporting characters like the servants. In case you don't know the story, the bones of it are the younger son asks for his inheritance, goes away and squanders it on wine, women and song, ends up in a pig pen and decides it would be better to be a servant at home than starving and comes home; the older brother stays home and tends to business; the father misses his young son, forgives him and restores his place when he comes home repentant; the older brother is angry about it all and is self-righteous. You can Google it and read the whole story.
These are not actual peop!e Jesus knew. They are a story about something that goes on in many levels - human family schism and problems; spiritually in our relationship with God; in our inner relationship with ourselves, etc.
At different times of our lives we can identify with each of the characters in this story. Perhaps we have made foolish decisions and have come seeking forgiveness. Or we have been jealous and judgmental, even self-righteous, about someone else's behavior. Or we have been the worried person and rejoiced when our loved one came back and greeted him/her with forgiveness and relief. Or we have turned away from God and had to walk a long path to come back. Or....
I think that in all great stories we can find the story of humans, including ourselves, and we can learn and grow from contemplating them, especially when we put ourselves in the shoes of all of the characters. They are after all about us, all of us.