The books I gobbled up when I was a teenager frequently took place during World War II and included characters who were part of the Resistance, groups of individuals who acted at great personal risk to oppose conquering enemies. I remember hoping I’d have their courage in similar circumstances. I feel very lucky I haven’t had to find out. Those stories, however, have given me the courage to move past fear on a few occasions. One New Years Eve I stood on a San Francisco sidewalk and yelled at passersby to draw attention to a man who was attacking a woman in shrubs next to a building. At first I…