Of membranes and stickybuns

I am verklempt.  Befuddled.  Bamboozled.  My understanding of physical laws has been turned upside down.
Seems I've been putting off my brushing up on modern physics for far too long.  You see, I've heard the phrase "string theory" bounced about the ether, but the text accompanying it always seemed to have enough density to generate its own gravitational pull, so I would constantly put off the reading. 
Now my head is paying for it.
I was educated in the "particle model" of the universe; that all matter breaks down into discreet bundles of bits that were always graphically represented as looking like marbles even though no one has ever seen one.   After catching a program on the Science Channel, I've learned that the particle theory has been left behind in favor of string theory, that (if I understand it) all matter springs up from the vibrations of tiny strands that make up the fabric of the universe.  The metaphor used to illustrate this was the plucking of a guitar or a cello string.  In this model, the universe is not made up of four dimensions, but ten.
Take that a bit further.  Membrane theory, or M-theory as it is often referred to as, adds yet one more dimension to string theory.  In this line of thought, all things are connected to and extensions of a universal membrane that is the unifying string, the 11th dimension.  This construct has been represented as something akin to a doughnut, or a stickybun, or maybe a Cheerio.  The Cheerio Model may indeed be a useful construct as there apparently can be infinite membranes representing infinite universes (a multiverse!)  And like all other things in nature, these membranes are in motion.  The moments when they come into contact with one another could be the spark that Big Bangs are made out of.  Just imagine Cheerios floating in milk, colliding and bouncing off each other.  Although the milk may be where my metaphor breaks down as it implies a medium and there doesn't seem to be such a thing, even though nature abhors a vacuum.  >exhale<
Ok, I consider myself a fairly intelligent guy.  Without trying to sound conceited, I'm a slight bit above Joe Six-Pack in the brains department the same way a marathon runner is above me in fitness.  I have a Masters degree, I scored high on the GRE, and I've never been to a NASCAR race or a WWF match in my life.
But I have no idea what any of string or membrane theory really means.  And I've been trying to parse it all.  Then I think back to the particle model and how no one has ever really seen an atom.  It makes me wonder if this is just our own heads trying to assign shape and meaning to things that we can't see.  We might get close to the reality, but we can never seem to see the whole thing, not unlike Plato's allegory of "the cave." It could be our minds performing a sublimation of intersticing patterns born of our own narcissism, our own pleading need to understand, to give shape to things that might not have any shape.  Is it all perception and psychology?
 
If anyone can explain these theories to me in a way that this physics flyweight can understand, I'd be grateful.  Perhaps via something that I understand, say...rhetorical theory or Victorian literature?

Speaking of reading, I'm still burrowing my way through Above Top Secret.  I'll write a review once I've finished. 

Follow me on Twitter: @Jntweets