How do I save a reference?

In Java Objects point to an area in memory where the relevant data is stored. When you name an Object, you're creating a reference by which you can access that particular area in memory. In this instance

Man man = new Man();

creates a Man (note - uppercase M) Object. The reference to this Man Object is man (lowercase m). If now you want to access this particular Object i.e. to assign a wife to it, you would access it by using the reference "man" that you assigned to it when creating the Object