Does AI show we overestimate our human creativity? And what does creativity mean anyway?

Among the angst over the creative potential of Artificial Intelligence, some researchers and academics are now turning the spotlight back onto humans. If AI can be as imaginative as your average human being, they ask, what does that say about traditional notions of human creativity? Have we long overestimated our own smarts? It's also prompted a discussion about what "creativity" actually means and why the term only came into common usage during the second half of the last century.