Do you feel uneasy when you see someone wearing a helmet and you’re not wearing one? Like what do they know that you don’t .-.

We had an English lad who came into the library with an army helmet on. I could not help laughing at him. Maybe he thought the books were going to fall on his head, or a rogue computer was going to attack him.
He was causing a distraction so I asked him to take his helmet off - he was most upset and left in a wee huff.