Final answer:
In 'Freak the Mighty,' Max tells his dad about what happened to his mom because he feels guilty and wants to confront his father.
Step-by-step explanation:
In the book, 'Freak the Mighty,' Max tells his dad that he remembers what happened to his mom because he feels guilty for keeping it a secret. Max wants to confront his father and share the truth because he believes it's the right time to do so. By revealing the truth, Max hopes to find closure and protect his dad from the burden of guilt.