Well, it does depend on the dog, not the breed. Every dog is different. There might be a one year old Terrier that is as calm as a 13 year old Terrier. There might be a dog who is 15 and is as hyper as a puppy. It really depends on the dog. You should be able to see your dogs acts (like you said 'your dog will run away when you let him off the leash') You learned that from him. Soon you will learn how long it takes for your dog to settle down