My room is a black hole.
My backpack is an abyss.
Why the difference?
My room is dark, no light enters it, and what goes in rarely can go out, or is ripped to shreds. I am the exception.
My backpack looses most things I put in it, and to get anything out of it, I have to summon them from its depths. Oh, plus, anything that goes in comes out a bit... different. And possessed.