Its all about association, that is how dogs learn. Dogs learn their good and their bad through association and most of it has to do with us. Though not all of it has to do with us and they get life lessons regularly all on their own. A life lesson dealt in the form of a guardianless correction can be a good thing but if it is a really negative experience you may then deal with fallout behavior. I was once in a field with Tilley where we were doing frisbee. A man and his young lab were doing the same at the other end of the field when the lab spotted Tilley, you always know when a dog is coming your way when you hear the frantic calls from a guardian. His posture was friendly so I wasn't worried, he really just wanted to come and meet my girl.
In an instant he was on his back, righted himself and was heading back to his owner. This young dog got a life lesson and it had nothing to do with his owner and he will probably not run off again for a long while. As this dog was running to see Tilley he did not see the soccer net before him and hit it full speed flipping him over instantly. He was so stunned that Tilley left his mind and he went back to the safety of his Dad. Being that this was a lab he probably got a great lesson, don't run away.
Had this incident happened to a more sensitive type dog it may have been a problem. He may never consider leaving his guardians side again and have skittish behavior when at the park which then must be dealt with by desensitizing. Another good example how association works is when something happens in a certain area like a room in your home or the car. Wherever the incident happens can be a bad place for the dog if they have a negative association happen there, they won't think about the incident but more so where it happened.
Good association examples are easy to find, like the lid of a cookie jar. If I am looking for my Jack Russell all I need to do is jiggle the lid and she is there. She knows that when she hears this particular noise that there is a good chance she is getting a cookie. Or when you put on a particular piece of clothing or shoes that gives your dog the heads up that you are going for a run with them. My husband runs my dogs every weekend so when he puts on his particular running shorts their ears go up and they watch his every move to see if he is putting on his running shoes as well. If he does the excitement level really goes up, its all assoication.
I recently had to take Tilley to the vet, I know she hates the vet and it is quite a tramatic experience for her. All my dogs know when they are at the vet before we even get in the door but Tilley knew as soon as she got into the car. She was alone and it is very rare these days that she goes out alone. She use to go much more often when she was more involved with frisbee but now that she is 10 she is almost always out with Luke. So to her being put into the car alone was not a good thing and she associated it with a negative. This is something I now have to turn around for her, which will be an easy one one to undo, a couple of fun trips out alone and it will be gone.
If your dog is displaying some unwanted behavior it may be caused by a negative association which you can figure out if you dissect both their behavior and your own. When Luke was young he quickly associated the word "come" to mean that a dog had just entered the park. Because he was not suppose to be off leash I would call him immediately when I saw someone with a dog come in, I knew he would run to meet the people so tried to call him before he saw the other dog and leash him. Before long when I called him he would immediately charge towards the entrance of the park, hows that for backwards training.
So this backwards training needed a tweak and because Luke is such a sensitive guy it took a while to change his association to the word "come." It is amazing to see how it all works, and the fact that you can't explain your way out or into situations with your dog is the reason you need to pay very close attention to what you are doing and what your dog is associating.