Okay kiddo, Girard's paradox is about something called the "prisoner's dilemma," which is a game where two people are arrested for a crime and are put in separate rooms.
They are given a choice to either cooperate with each other and stay silent, or betray the other person and confess to the crime. If they both stay silent, they each get a small punishment. But if one person betrays the other, they get a really good deal and the other person gets a really bad deal. And if they both betray each other, they each get a pretty bad punishment.
Now, Girard's paradox is when people keep playing this game over and over again. Sometimes, even when it's better for both people to cooperate, they end up betraying each other because they don't trust the other person.
This paradox happens because people start to think about what the other person might do instead of what's best for themselves. It's like when you're playing a game with your friend and you think they might cheat, so you cheat too just in case. But if both of you just played fair, you would both win more often.
So remember, sometimes it's better to cooperate and play fair, even if you're not sure what the other person will do. That way everyone can win!