My therapist introduced me to the idea that we can think to ourselves, "I don't get it" when people start playing mind games. I've had encounters with people wherein the group dynamics become so heated with vague accusations and gossiping that it becomes very difficult to untangle what is going on- or create some kind of narrative with which to describe the dynamics to an outsider. In those situations, instead of trying to untangle or describe, I just think to myself "I don't get it."

You could also use this phrase if someone tries to drag you into some kind of argument or fight. It is true- fights don't make much sense.