The phrase has never suggested to me the inherent difficulty in the actual invention of the wheel. After watching this outstanding video, I think we can recharacterize the metaphor to communicate the immense amount of ingenuity, interconectedness, and iteration over thousands of years that has gone into creating even the most basic building blocks of modern life. Certainly we don't want to reinvent the wheel given all that, but we should learn more about the infinite complexity of the world around us, and in doing so strive to make a better wheel.