Here's why:
* Art is a human expression: It's not a person with a birthdate. Art is created by people across time and cultures.
* Art is an evolving concept: What we consider art changes over time and across different societies.
* Art has no single origin: Art forms have developed independently in various parts of the world.
If you are interested in a specific art form, like painting, sculpture, music, etc., you can look up the history of that form and its origins.