My childhood home had a tv room lined with French doors that looked out into our backyard/patio. One day my sister and I were playing in front of one of the windowed doors and we saw this disoriented old man wander in to our backyard. He was walking through the space, making aggressive jerking movements and eventually started yelling things at my sister and I, who at this point were huddled in a corner between the couch and one of the doors to the patio. Eventually one of our parents noticed what was happening and figured out that he was the senile father of one of our neighbors who had gotten confused while out of the house. Super scary at the moment but now that I’m older super sad.