Theory of Mind is about as close to mind-reading as people can get. Most formal definitions go along the lines of the ability to discern the intentions, and motivations of yourself or another person. To develop a Theory of their Mind, hence the term. I think it has two components to it, especially if you're talking about one person trying to understand another's behavioral space.
First, it's the ability to penetrate inside someone else's psychological interiors and understand the rewards and punishment systems inside that interior.Second, it's the ability to understand at all times that the rewards and punishment systems inside your head are not necessarily the same ones inside your neighbor's head. But he or she is not going to react like you do because he or she doesn't have the same rewards and punishment systems you do.
I joke in the book about calling the following saying John Medina's Second Law of marriage. Here's the saying: what is obvious to you is obvious to you.