This incident is when Freak and Max decide to perform a kind act by returning a purse to the woman whom it belonged to. Unfortunately, the residents of that particular household were not reciprocating the kindness that Max and Freak had displayed to them. Instead, they were thrown with insults and as Freak and Max were leaving the wretched household, Freak caught the heaviest insult of them all.
An excerpt from Freak the Mighty: (here, Loretta, the rigid lady, is conversing with Freak)
"...I know all about you. Your old man was a magician, did you know that?" ... "Yeah," Loretta says. "Right after you was born. He must be a magician, because as soon as he heard the magic words 'birth defect,' he disappeared."
This is the absolutely adverse way to behave with a person that found your missing item and made the effort to return it to you. In fact, you should never, under any circumstance behave with such a nasty matter towards anyone. If everyone kept putting each other down, this world would be lifeless. None of us would desire to live in a place like this and everyone would just be there. Without a purpose, without a goal, without something to live for.
So make your life purpose-filled, goal-occupied, and with someone or something to live for.