Had a fair few years of this myself. When we lived in the top flat above shops we had a rather horrible downstairs neighbour. My daughter was only about two and she used to toddle up the hallway to our bedroom. Well that started a rather unpleasant bout of the neighbour banging her flat door closed, which made us all jump out of our skin. After this, any time my daughter made even a slight noise she would bang her flat door. It was like living on a knife edge and to this day has made me jumpy about people making a noise in my house. The next thing that happened was when it became obvious I was pregnant with my second child, she'd shout out as we were passing her flat (to access the main street door) that we were 'breeding like rabbits'. My then husband was from India, and we were also racially abused by her. My daughter is now 45 so it was in the days when racial abuse was not a crime in the legal sense. It wouldn't happen today so blatantly, but it was highly unpleasant and has left a lasting effect on me. These days she'd be taken to court and prosecuted.
I've got another 'keen'... Ouch!