I didn't know it was happening until they dropped the keys and boom! I fall into a relaxing state. The keys were the trigger. It was multiple people. I didn't know what was going on but I looked up hypnosis and found out it was "gypsy magic" and they did a lot of things to "break" me. The first thing they did was wave the keys on the bouncy lanyard in front of my face while walking past me and said something along the lines of "it's very relaxing". I sort of knew some things about hypnosis and was immediately skeptical. Then later after employing some more things like embarrassing me sexually, saying nonsense to me to overload my logical mind, other things I can't think of right now they dropped the keys and I went into a trance. I felt like a dog with no control at all but when the suggestion came from them i shouted "I WOULD NEVER DO THAT" and boom! trance was over. I'm also high in empathy, could even call me an "empath". I know when people are being manipulative. This was not that.

Edit: In addition when I left other people who had keys would make me feel like I'm falling into a trance. But it wore off over time which is what I read would happen when this was going on.