Did you ever notice, when sitting at a train stop or public area, most people barely look at each other and interact unless something relevant to all is going on. But take your dog to a vet and watch how people interact. It's amazing how people will comment on others dogs, and just generally chat away about the dogs and other things, without any walls up between them.
Although on some occasions it can be devastating. We had taken ours in for the final visit and after we came in, a young family with a new pup came into the waiting room. When we were done, we stepped outside with red eyes and just a collar and a leash, just heartbroken. The little kids (maybe 3, 5 and 7 years old) looked up and didn't get it. The young mom's smile just receded when she put it together as the pup frolicked with the kids. You could see her face go from a welcoming smile to a look of fear/compassion as the realization of what lies ahead for her and her brood in 10-13 years. She just shooshed the kids as we made the quick chat at the desk for final billing and as I looked back as we were leaving, she was clueing the husband in on what just happened.