I forgot my glasses at a fitness class and could only see vague shapes across the room. One person near the wall seemed unusually friendly. I waved; they waved back. I stretched to the left; they did the same. I smiled; perfect synchronized smile. I spent several minutes thinking I had made a new gym friend before walking closer and discovering an enormous mirror. I had been greeting myself. That would have been survivable if the instructor had not stopped beside me and said, "Great connection, but your partner looks tired." Several people had been watching the entire relationship develop. For the rest of the class, every time we changed positions, someone waved at their own reflection. At the end, the instructor told us to thank our partners, and the whole room turned toward the mirror. I now bring spare glasses. I also avoid gyms with emotionally available reflections.