It means that nothing actually exists except for the experience. And you are that experience, thus making you the universe.
It is incredibly simple in concept, but difficult to wrap your head around. Still, it's true. You are the universe experiencing itself. All the evidence that we have points to this very truth. Life is dynamic. Evil defines good, hot defines cold, dark defines light. None of these is mutually exclusive, as in, good would be nothing without evil... literally nothing. So the ebb and flows of dynamic experience coagulate into something apparent. That apparent something would be you. The universe is impossible except within this frame.
There is no god. Sorry. Evil in spite of a purely loving creator? I don't think so. Matter and energy cannot arbitrarily exist. Sorry. Stephen Hawking, in his latest book, surmises that matter came into existence spontaneously with anti-matter as a by-product. He's a smart guy, but if that sounds like a stretch, let me run this by you.
Nothing... as in, "nothing"... like a lack of anything... cannot exist. The experience itself, while apparently tangible, is not. The good in the world is equivalent to all the evil, because they are utterly relative and dependant on each other. They net zero. Like everything else. They cancel each other out.
The fact that there are waves doesn't change the volume of water in a lake. When it all stands still, the dynamics are over. The cycle of death and rebirth can finally end. That is the enlightenment that Buddha was talking about. Meditation is training to still the spirit/soul/self. The only way to truly end suffering is to end all passions.
It is all a grand illusion, but it all seems so real because you, my friend, are the universe. And with that, you and I, and all of us, have the power to change it all.