It'd be easy to break Freak the Mighty into a simple black and white scenario: Freak is smart and Max… isn't. But you Shmoopers know that things are never as simple as they seem. Even if Max calls himself a "butthead," there's more going on upstairs than he thinks. Over and over in Freak the Mighty, he proves that he's one smart dude. What's the lesson? You don't have to be Freak-ishly brainy to be smart.
Freak is smarter than Max. That's just the way it is.
Freak is able to help Max in school because he understands him better than his teachers do.