This is the most logical conclusion one can get to when we consider the fact that there are stories of floods in most cultures.

That would be the Great Flood, such a traumatic event that it remained ingrained in the collective memory of human kind and was retold in legends.

There are in Venezuela many picture books, adapted from oral tradition, desccribing the beliefs of ancient native venezuelans. Some of them depict the emergence of light (Dueño de la luz), creation of animals and plants and the famous flood (The Great Canoe a Kariña legend, adapted by Maria Elena Maggi).

I also like the idea of alien civilizations behind our race, unfortunately,there is little evidence of that and after so many efforts to contact or reach other worlds with similar life possibilities nothing has been gained.
Our generation and our children's may die without ever knowing for certain what the truth is.