I've thought the same thing, think of this however, relative to an atom, the atmosphere around it is vast and seemingly endless. Imagine the world as an electron, orbiting a nucleus, the possibilities of what lies beyond space are endless especially when realizing that at a subatomic level the laws of physics change, making it entirely possible to believe in the possibility that in an environment where we are a subatomic element the laws of physics may be entirely different, even time flow itself may be at a different rate. But even in this instance I cannot imagine what would exist beyond that, and furthermore. It would seem the actually existence of an infinity is very difficult to except. I think the best way to even look into this is to first determine, what is space? Does it have an ecology etc... I hope someone finds these answers during my lifetime.