I wondered about that too sometimes, sort of, when I was 10-14ish. My idea was that our universe was a proton or something on a HUUGE level, and that our protons are universes on a smaller level. It made no sense, though, cuz as you get smaller and larger, it's just a ridiculous infinitesimal WTF. I decided to close it off, make it a loop. So our universe was a proton in another, which was a proton in another, which was a proton in our universe. It still makes no fucking sense at all. Eventually I decided, 'fuck it, I know what I can perceive. Everything else isn't worth bothering with, as I'll get no where. Anyway, I believed in god at the time, and simply thought that he existed on another level of perception. Not like I thought in those words when I was ten, but that was basically the idea. So I said fuck it with explaining god as well when I decided to fuck contemplating the universe. Even if I did figure that shit out, I'm just going to die anyway and it won't matter then.