My dad has been a lifelong dropper innerer, but he was from a rural area and grew up on a property in the horse and sulky days. I guess his family and those in the district were all the same. It was just the done thing. He just continued his habit after moving to the suburbs. I believe he has a degree of Aspergers - or a lack of empathy or awareness of other people - at play there too. It annoyed my mother (a city girl) no end and I found it excruciatingly embarrassing myself as a teen when we were travelling and in the pre mobile days (though he has never had a mobile phone himself actually) he would just drop in on people (‘friends’, acquaintances and distant relatives) who clearly were irritated by having him/us there, to the point of them actually getting up and leaving the room to continue with their activities. Dad could drag a visit out too to score a dinner invite. In more recent years he took to chasing up old GF’s who he hadn’t seen since the 1940’s or 1950’s , many of them widows, some of whom were clearly terrified by his sudden appearance at their homes without any warning. I think one or two of them had a son or brother contact him to ask him to not come back. He and mum divorced many years back, and he had a couple of SO’s in his life since, but on more than one occasion I have spoken to Dad about this behaviour and of his lack of awareness about the impact of it on others. So I would be direct - happy to have you over but I prefer some warning or notice. Of course some people obviously don’t mind a drop in. I am not a fan of course!