Dogs have many great traits. Each one has a unique personality that is derived from their upbringing, socialization and you. If you treat your dog like a spoiled little person, you are going to get a spoiled little dog. If you allow your dog to learn how things work in the dog world on its own, then you are going to have a very nicely adjusted dog.
I let my dogs be dogs. They learn by interacting with others on how to behave. This is the way nature intended it. Some dog owners feel that their dogs are not truly dogs, but furry fragile humans. They are not. They are more like little kids. Kids and dogs are similar in that they both want to get dirty, tease others, run at full speed, push limits and form friendships. If you shelter your kids and are overbearing and overprotective, you produce kids with social issues. Well, guess what? This is another similarity that kids and dogs share. If you yell at your dog (or other dogs) because they are playfully growling, rolling in the dirt, barking to be chased or basically acting like a dog should, you take away your dog being a dog. Your dog then becomes like you and starts responding negatively to "dogs" and poof! You have created a spoiled little dog.
They say "Let kids be kids, they can grow up later". Well, let your dog be a dog. They will sort it out just like the kids do and they will grow up well adjusted and slow down some. Do not allow your fears or overbearing persona control you and how you respond to your dog. I am not advocating letting your dog get hurt or traumatized. What I am saying is that you need to know your dog well enough to know what it is saying. Look at how your dog is playing. Listen to the different barks, tones of growling and watch their body language. They will give you cues to what your dog is feeling. Some play rough, some don't. Some sound like they are killing each other, some are quiet. Some like to roll on the ground, some like the chase. Usually, the dogs in the group will figure out who is who and play according. If you feel like there is a bully after your dog, ask the owner (politely) to have their dog stop. Do not yell at your dog to stop. It can only confuse your dog. What may have sounded bad, may have actually been fun for your dog and it may not understand what it was doing wrong. Try to keep the dogs apart for a few minutes and if your dog keeps going back, and there is no aggression, then your dog is not feeling threatened. This may be a new side of your dog. Relax. They will let you know.
The point of all this is the joy of having a dog is watching your dog in the world around it. Whether it is catching a Frisbee, rolling in the mud or chewing on the leg of a friend, your dog knows how to take care of itself more often than not. If you allow your dog to be dog, you can be a more relaxed owner and you will enjoy each other even more.