By the end of Freak the Mighty, Max might have escaped his father, dealt with the death of his mother, and suffered through the death of his best friend, but he still has a tough battle ahead of him: his own self-image.
See, Max thinks he's a real dummy. We as readers know that he has proven himself on several accounts and even Freak, who knows everything, sees that Max has more potential than he acknowledges. And leave it to Freak to take some action, giving Max a blank book to fill with their stories—and Max's potential.
And after Freak passes away, Max finally lives up to that potential. He tells us his story with his own words—not Freak's, not his parents' or grandparents', but his words. As he puts it, "the unvanquished truth" (25.19). Freak lived more in his short life than some people live in their whole long lives, and Max takes his cue from his friend. All he needs is a little shmoop from Loretta who tells him to do something because, hey, "Nothing is a drag, kid" (25.16).
So Shmoopers, what "something" are you doing?