Actually, it's in your head... as everything like that is in all our heads...and not a physical concept, but something we create in the form of thoughts.

Does your mother ask you to wash her toothbrush? I think it's ok to do your own stuff, but probably not a good thing to mess with other people's things, you know? You have enough to worry about for yourself.

Yeah, breathe... it's good for all of us.