At the beginning of Freak the Mighty, Max wants nothing more than to be left alone. Actually, that's kind of an understatement. Max knows that if you don't get close to anyone, then you can't lose anyone—so he stays away from everyone. And then along comes Freak, breaking Max out of the down under and out of his safety bubble of isolation.
Max isn't isolating himself from the world. He's flat out hiding from it. That's right—he's scared.
Max and his dad are similar in how they try to remove themselves from society.