In ancient Greece and Rome, there was a very popular form of literature called aetiology. (This same word is used in modern medicine, where it is more often spelled "etiology.") This word comes from the Greek word aitia, which means – get this – both "cause" and "blame." You can see how it can have these two meanings if you imagine aetiology as about finding out whodunit: you want to find out who the cause of some action was, and you might want to blame them too. Many of the transformations in Ovid's Metamorphoses could be interpreted in terms of aetiology. This is because, in many cases, Ovid tells a story about how something became the way it is today by pointing to its past. For example, he says that the island of Icaria got its name because it was near where Icarus fatally crashed into the water. Because of its interest in aetiology, Ovid's poem is profoundly interested in memory and the past.
Ovid thinks the conflicting stories told by humans make true knowledge about the past impossible.
Ovid is more interested in telling a good story than in telling the truth about the past.