Along the same lines as the last post, see the dark matter video here. The main point is quite true. We can make accurate predictions about gravitational fields, and about electromagnetic fields, but in fact we have no idea at all how/why they work. Oh, physicists can write equations about them, and speculate about fields being mediated by various theoretical particles with cool names like the Higgs boson, or the graviton, or the gluon, but fundamentally we still really don't understand how the world around us works. There is still plenty of scope for the next Einstein or Galileo or Copernicus.
Kids ought to be taught this, and their imaginations fired by it.