The Theogony Vs. The Yoruba Creation Myth

Have you ever wondered why so many myths from around the world have so many similarities? The Eldar Eddas and The Rig Veda both begin in chaos. The Theogony and The Enuma Elish both contain Bloody Struggles. Even Genesis and The Yoruba creation Myth contain a flood. Why would so many creation myths have so many similarities? As far a creation myths are concerned three motifs continue to appear: The idea of floods, The idea of a bloody struggle, and The Idea that the world began in chaos. Floods Most creation myths seem to at some point have a flood pop up in them. Who really knows the reason it could have been ,because floods naturally occurred in the areas these were written. According to Genesis and The Theogony people were wiped out by floods, because they were evil. Maybe the people of these cultures just thought that people were evil and deserved to be wiped out.
Another possibility is that maybe a lot of people of these cultures were killed by a flood. It is a possibility that these cultures could have had a big flood, because the people that created the Yoruban, Christian/Hebrew, and Greek myths were all close to water and the ocean. That brings me to the next thought maybe they had just seen the ocean and assumed that as vast as it was that the earth had flooded at some point. Which actually could have
Creation myths like The Elder Eddas and Genesis had began in chaos. One speculation for this is that most things (when people are involved) begin in chaos. Order is not a thing that happens it must be created by a leader. Most of this civilizations must have known that and created a god that could make order for the universe itself, but that might not be true though. It is also possible that they just believed that the world began in chaos, because it was easier and more interesting than believing that the world began in