Yes, and my response to what Mickey said was that why would we think that we're in the cave looking at shadows? Why should I complicate my view of the world with the added baggage of metaphysical idealism when materialism works just fine to explain everything I see? Sure our perception of the world is limited to our senses and measurement techniques, but the scientific framework we've built onto that base appears very consistent and functional with its predictive power. It's definitely not omniscience, but it works.
I only brought up the Cogito argument to point out that Mickey is incorrect in saying that no certain knowledge exists.