In terms of adding authenticity and credibility to your writing, this ongoing observation is vital. Seek out experiences that challenge your fears. The ability to see the world from the perspectives of others is critical for creating real, developed, unique and interesting characters. Without this ability, all of your characters will be more like stereotypes or merely represent aspects of your personality. Yet by confronting your own fears and discovering why people pursue the experiences they do, you will have a greater insight into the extraordinary diversity of human behavior.
Fear is one motivation for human beings that was discussed above.
You will also be able to construct more complex conflict between and, more importantly, within, individuals. Never forget that conflict is the essence of all drama. This conflict may be physically acted out but it is usually a manifestation of conflict between ideas, values, beliefs and traditions. Yet this ideological conflict was physically contested. Use the right tools.