Of mice and men is about relationships between people. Surface-level character traits can hide more complex traits. What can we see beyond the characters actions?
This really depends on the particular character you are referring to. One of the major themes of this book involves the intense isolation all the characters feel. They try to mitigate their loneliness in different ways (drinking, visiting brothels, wandering the ranch...) but cannot escape the futility of their lonely lifestyle. All characters dream of a place of belonging that offers identity. They simply exist at this ranch unable to reconcile their reality with their longings.
