If it makes you feel any better, I may as well be badly afflicted by dyslexia when I try to read a mathematical statement with more than a couple simple terms.
[0] I'm digging way back so this might be a little off, but fundamentally it's a solution to the Problem of Evil[1]: Leibniz puts us each in a "windowless monad" of a universe—sort of individual pocket universes—such that all the people we interact with are actually automatons of a sort. In this way, a person can do evil (i.e. sin still exists), but not actually inflict it on anyone else, if that makes sense. Meanwhile, bad things happening to you in your personal monad aren't actually evil because... I dunno, it's been a while so I don't remember exactly, but I'm guessing it comes down to "God works in mysterious ways". Basically, he replaces true causality with a kind of divine harmonic dance of actually-not-affecting-one-another things and people that make up what we call "reality". Nb. his actual argument is far less dumb than I'm making it seem.
[1] The Problem of Evil can be summed up in the child's question: "if God's perfectly good, and created the universe, why does evil (apparently—that part will matter a ton for some people who try to address this) exist?" Lots and lots of theologians and philosophers over many centuries took a crack at the seemingly-simple question—and in fact, one of Leibniz' notions, that the world one experiences is "the best of all possible worlds", was famously parodied in Voltaire's Candide, which is another way someone with a humanities background might have become familiar with his philosophy.