I once got into a scientific discussion on my doorstep with one, about evolution. He tried to tout the idea that it would be impossible for eyes to evolve gradually. Unluckily for him I’d been reading a lot of Dawkins. Ran rings around him and he eventually said “well I’m not going to convince you” and left. He knocked on my door again the very next day, only this time he had a friend with him. And that friend knew more about science and biology than he did. He literally brought back someone cleverer than him to “own” me. Only I’d done some more reading the previous night, based on our previous discussion, and I was well equipped to humiliate the friend too. That was the last visit I ever got from them.