I think all friendships should be based on the premise that at any time I could knock on a friend's door and no matter what, even if they're laying on the couch and peeking out through the blinds and see that it's me and don't answer the door because it's "one of those days" that I will never be offended... and vice versa. It makes me want to be with friends more that are able to say "no" when "no" is needed in their lives-- it make the "yes" times a whole lot funner because we know we are all there because we want to be.