No, I wasn't. So now its too late for the Big Bang to predict it for me.
Its absolutely tiny anisotropy fits superbly with our expectations of an expanding universe.
"Anisotropy" is not even in my vocabulary...seriously what does it mean?
I am not aware of any rival explanation for CMB.
Don't feel bad. I'm not aware of a lot of things, quantum mechanics in particular seems to give me trouble. I can start to follow it mathematically, but I just can't get an intuitive feel like I get with good old Newtonian physics. But God help me in figuring out why the universe exists at all.
Here is a quote I found that helps to describe the phenomenon for those of us (including me) with a relatively modest understanding of physics:
Why does the CMB support the Big Bang picture?
The basic point is that the spectrum of the CMB is remarkably close to the theoretical spectrum of what is known as a "blackbody", which means an object in "thermal equilibrium". Thermal equilibrium means that the object has had long enough to settle down to its natural state. Your average piece of hot, glowing coal, for example, is not in very good thermal equlibrium, and a "blackbody" spectrum is only a crude approximation for the spectrum of glowing embers. But it turns out that the early Universe was in very good thermal equilibrium (basically because the timescale for settling down was very much shorter than the expansion timescale for the Universe). And hence radiation from those very early times should have a spectrum very close to that of a blackbody.
The observed CMB spectrum is in fact better than the best blackbody spectrum we can make in a laboratory! So it is very hard to imagine that the CMB comes from emission from any normal "stuff" (since if you try to make "stuff" at some temperature, it will tend to either emit or absorb preferentially at particular wavelengths). The only plausible explanation for having this uniform radiation, with such a precise blackbody spectrum, is for it to come from the whole Universe at a time when it was much hotter and denser than it is now. Hence the CMB spectrum is essentially incontrovertible evidence that the Universe experienced a "hot Big Bang" stage (that's not to say that we understand the initial instant, just that we know the Universe used to be very hot and dense and has been expanding ever since).
In full, the three cornerstones of the Big Bang model are: (1) the blackbody nature of the CMB spectrum; (2) redshifting of distant galaxies (indicating approximately uniform expansion); and (3) the observed abundances of light elements (in particular helium and heavy hydrogen), indicating that they were "cooked" throughout the Universe at early times. Because of these three basic facts, all of which have strengthened over the decades since they were discovered, and several supporting pieces of evidence found in the last deacade or two, the Big Bang model has become the standard picture for the evolution of our Universe.