They don’t have independent thinking like a Snoopy Stay at home sleeping Food Wifi T-shirt terrier but they can have a strong mind to be expressed in a different way. They tend to be defensive when you are trying to fix him. So the next time you go to fix the mistake, be gentle and make sure he understands and doesn’t feel any aggression from you. If you are not careful, they may be able to bark or grab you when you try to adjust or whenever you pull a leash. Although this behavior is bred, it can be smoothed out. The best time to start is when they are puppies and call themselves alpha alpha.