@Mountaindewed I had a neighbor at my last house who was bizarre from day one. Her yard was beside my bedroom and she'd sit in her yard and stare at my window. She encouraged her yippee little dog to bark at my cats (who were inside the house minding their own business looking out the window) and she just did weird things. She was also rude. If I had guests over and wanted to use my patio she'd have her dog out barking at us until we gave up and went inside. We were neighbors for 10 years and although I smiled at her and said hello if I encountered her we never spoke. She seemed absolutely paranoid about me. Things just got weirder over time and that was when i became pretty sure she had dementia. Some of what she did was still creepy but people with dementia are mostly harmless and she ever did anything bad, just rude or thoughtless depending on how much she was in control of her actions.

I did learn when I sold the house and a survey was done that I'd been mowing a decent sized chunk of her yard for 10 years.