It is rare that I wish I had more math ability
But reading Brian Greene's The Hidden Reality made me think that I should have done more in college. It is about the various ways there could be multiple universes. Besides physics, the book incorporates a bit of philosophy in ways that made it far more interesting to me than The Elegant Universe, which i struggled through 8 or so years ago.
The first way is the easiest to understand by far. If our universe is infinite, really infinite, not just really really gigantically large, then there would be all these galaxy groupings that didn't overlap because light hasn't had time to travel between the groupings and each set would be it's own universe. It that's so, there's only so many ways all the particles can align and eventually the alignments would repeat, creating a Milky Way, a solar system, an Earth exactly like ours but so far away we'd never meet them.
Another that isn't terribly difficult to grasp is the simulated universe. As I love the Matrix movies and have enjoyed the various philosophy essays i've read regarding the movies this section also felt familiar. Basically, people love to play God (I'm looking at you, Sims players!). Eventually, if we don't kill ourselves off first, we'll have the computing capability to recreate our own reality. If we can do that, we probably will do that, and if you tie that idea back into the infinite bit earlier, the chances grow that we've already done that and are actually in some simulation right now! However, i've been trying to free my mind and learn to fly since 1999 and it isn't working, so i don't buy into this part of this theory. ;)
But the parts about braneworlds, the quantum multiverse and the holographic principle left me struggling, especially the last. Greene does use lots of tables and pictures which do help. It was in these portions that I wish I could have done a bit more physics, and even math, in college. I know i could have handled more physics but I barely got a B in Calculus my freshman year, and that was because I had taken an entire year of it my senior year of high school. I really don't think I have, or had, the brainpower for more math.
So, overall, this book is a 6. If you like some pretty hard core science you may enjoy this book. If the thought of the cosmological constant, Planck lengths, or Hawking radiation makes you queasy, skip it.