I have a theory about this, albeit bizarre

There is also another theory, well, there are prabably many, but I recall this one:

It's along the lines of parallel waves of time. Each wave contains us, just like we are - our lives, our universe, everything - only each wave is slightly different.

For some reason these waves are overlapping each other, and the contents of each wave becomes distorted and different. It does give some credence to why some experience it, and others not, as some people may be exactly the same in one wave as they are in another.

I don't recall the reason for why the waves may be overlapping, but I have a speculation that it may have to do with the ending cyle we are in due 2012.