When you think about it, we're essentially toroidal. In a topological sense, stuff that passes through our alimentary system doesn't actually go inside of us. Although when we swallow a donut, it feels exactly like it's inside of us. That's because the difference between you and the world is a perceptual construct- the actual edge of you is as hard to define as the upper boundary of the atmosphere. As far as the universe is concerned, there's probably no big difference between you and the rest of itself. And of course to the atmosphere, I'm just an ambulatory man-shaped bubble.