Different people has different idea on what dog socialization is. To me, this picture of a big rock firmly sitting in a fast flowing river is socialization. A well socialized dog is well aware of other dogs, people, sounds, floor surface, smells, food, cars, squirrels...etc around him; but the dog's attention and his trust is firmly planted in his handler no matter what, just like how the rock sits firmly in the middle of the stream unmoved by the current.