What about perception?

that's not between us, it's part of us

What about my underwear. They're like almost a part of me, but aren't. And What do I care what that old guy from Everyone Loves Raymond thinks. He's dead anyway so he couldn't have been that smart.

If your underwear are almost a part of you, then you need to change them more often.

There's always the atmosphere.

not to mention the roof of the house you are in when commenting

See, I think I'm thinking of the universe on a metaphysical level or something. Aren't we part of the universe and inside of it?