I think a true polymath would enjoy himself or herself in any time period. The further back you went, of course, the closer you could have come to mastering multiple disciplines. Now people in parallel fields scarcely know how to talk to each other, never mind integrating the bodies of knowledge in their specialties. I don’t know how anyone can even be a generalist any more. I remember reading that Aristotle (wasn’t it Aristotle?) was the last person to know all there was to know in all fields of knowledge. But of course that didn’t include the vast stores of learning already accumulated in cultures that the ancient Greeks had not yet gained exposure to. In fact, from a present point of view that seems like a very naive presumption. Nevertheless, I think Aristotle must have had a blast being Aristotle.