If you think you can trust your senses, or that what you believe must be true because you believe it, then you need to read Plato's Allegory of the Cave. Not that this will change your mind, of course, but it's a step in the right direction.
http://en.wikipedia.org/wiki/Allegory_of_the_Cave
http://en.wikipedia.org/wiki/Allegory_of_the_Cave