Interesting. This sounds quite similar to transcendental idealism, then. Or even Stoicism, or Vedanta. I think Plato would agree with this idea too, seeing his cave metaphor: We are prisoners in a dark cave, facing the wall. A fire burns behind us, casting off shadows from object passing between our backs and the fire. The shadows aren't real (actually, they're the absence of light), but to us, they _seem_ real. Same idea in The Matrix.
Nice.