You want to talk about the past? Freak the Mighty has it all: avoiding it, altering it, and straight up facing it. Max is so haunted by his memories of the past that he tries to totally block them from his mind. Compare this to Freak, who tries to remember everything—even things that never actually happened. See, Freak knows he won't get to make memories for long, so he relishes the ones he has. And we're pretty sure Max will do the same; he may not have Freak anymore, but he has the memories of all the time they spent together.
All the characters in Freak the Mighty are hiding from their past in some way.
Max's grandparents blame Max for what happened to their daughter.