Sometimes people are constitutionally unable to travel their inner world. They cannot exhibit enough conflict and contradiction that we recognize them as belonging to our complex human race. That is, they do not seem capable of change. They lack traits and desires that are at war with the world and other people. In other words, bland as oatmeal, without the raisins.
In fiction, however, such a character can be a great set up. Was he always bland and boring? Why? What can be done to make him feel? Perhaps as a writer, you can grant him the opportunity to enter conflict and thus discover his own desires and contradictions. Most of us are gentle, violent, tough, fearful, lusty, prudish, sloppy and meticulous--all at the same time.
Oh what fun to pierce the world of a protagonist and make him squirm. Get to his core. Thus, the plot starts.