Both Benson and Randy are victims of incestous abuse when it comes to their mothers in specific. I think about that a lot, how they have so many parallels—as we already know, but this one stands out to me more than the rest. Randy's mother is overbearing, and even controlling of the way he dresses, which is a pretty telltale sign regarding the nature of their relationship and the projection that Randy's mother puts onto him.
At 21 years of age, where Randy should be able to go out and drink and be his own damn person, he's still got his mother telling him where to be. What to do. What to wear. But Randy worries about her, he panics if he doesn't pick up in time, and he thinks his mother has a point when she decides to step in, because he doesn't think he deserves to make any kind of decision of his own.
Benson recognizes this practically immediately. When Randy mentions that he got held back in 2nd grade, Benson is so shocked that this could happen to a child, he determines right away that this must have been some sort of cruel and humiliating punishment. He's right, it is embarrassing for a kid so young at 7 years old to have to be singled out and held back a year because his mother thought it would be what's best. He wasn't allowed to move on from it because his mother didn't even let him to grow up with the rest of his class. No, he had to sit through 2nd grade all over again under the impression that this would have never happened if he never did that to Beard.
It makes sense for Benson to have caught on that this was abuse to some degree, because the wellbeing of children is so, so important to him. That is some over-parenting bullshit. He is so quick to start insulting Randy's mother who he is hearing about for the very first time because he's already got such a bad taste in his mouth after hearing that she could do such a thing to her 7 year old, and now look at the little pussy he's grown up to be, wasting his life away allowing himself to eat floor burgers. It makes him sick.
The thing about Benson's mother, however, is that she has instead neglected him. Earlier in the film, he expresses to Randy after getting him to admit he is a virgin that he believes that "all of the world's problems" can be blamed on people having kids too young to be able to raise them properly, and then allowing themselves to get hooked on meth. It is no secret that his mother is an addict, so it becomes clear that when Benson said this, he was speaking from experience.
His Ma was too fucked up on drugs to even notice the shit that happened to him in third grade, and even contributed to the hard, abusive mindset and worldview that Benson currently has. You can tell that the words Benson tells Randy after leaving his house, You make me hurt you when all I want to do is help you because I care about you, is something he is regurgitating after hearing it time and time again out of the mouth of his own mother. This is what it means it love somebody. Sometimes you have to hurt them to make them understand, especially when they have nobody else.
Now, Benson hates his Ma, he hates the home he is in, and tells Randy to just forget about that house, but we still see him be so affectionate towards his mother. Even after all this time, this is the woman that raised him, gave him life, and endured the hardship of addiction. How could you blame her? How could you leave her even after all she's done? Look at the state she's in, she can't even get out of bed, for Chrissake!
There's a string that Benson has never severed away from his ma, and yet he tells Randy to get the courage to break free from the threads that his mother has him entangled in.
