You may never learn the names of any of the people you talk to in a dog park even after many many hours spent there with them and many hours of conversation. But if - knock on wood - anything should ever happen to your dog these nameless non-strangers will rally sympathize offer to help and hold your hand. I know this from experience.
I lived on the top of one hill and the school was at the top of another hill. Nobody ever went to school by car - we didn't have any cars during the war. So that to and from school was itself a training.