Our neighbour recently removed some trees and we now have a view directly into their backyard. Which is OK as the neighbours are pretty quiet and don't seem to be around much. But I am thankful it wasn't done earlier.
The previous neighbour had a motorbike and used to ride in circles around his backyard, which I found very strange considering he was a grown man that could ride on the streets anytime he liked.
What's the strangest thing you've ever seen a neighbour doing?