Blame Bob Kane.
It’s the cornerstone of the Batman mythos–young Bruce Wayne witnesses his parent’s death at the hands of a criminal and that one events shapes his entire life. It’s an event that virtually every retelling of the Batman story has to include, with varying degrees of success. (Interestingly enough, both Tim Burton and Christopher Nolan found it necessary to tie the original killing into the main storyline of their films.)
Perhaps the most insightful story written on the thesis is Alan Moore’s The Killing Joke, which posits a similar origin for the enigmatic Joker, and asks some disturbing questions about how we choose to respond to life changing events.
I know that I am blaspheming against one of the most revered canons of American popular culture when I say this, but the Batman origin story is sloppy, lazy writing.
Bob Kane and the rest of the writing staff at DC comics can, perhaps, be forgiven for cutting some corners with their characterization–after all, they were producing a product designed to be heavy on action and light on introspection. As a comic book character pitch, “man becomes crimefighter to avenge the deaths of his parents” works.
Unfortunately, the popularity of Batman as a cultural icon inspires writers to take the same shortcut, and in a book intended for an adult audience, it doesn’t work.
I’m sorry, but people’s lives aren’t really formed by a single incident, traumatic as it may be. Yes, traumatic incidents do leave marks on a person, physically and psychologically, and I don’t mean to in any way minimize the experiences of those who have endured violence in their lives.
What I do mean to say is that I see too many writers taking the easy way out when writing motivations for their characters. Instead of taking the time to get inside their character’s heads and see the world from another perspective, they just invent a tragic backstory and use it to explain everything. (In the recent film Wreck-It Ralph that trope is lampooned brilliantly in the character of Sargent Calhoun.)
It’s a cheat, and it’s not realistic. People’s personalities are formed over time, by repeated events. Post-traumatic stress is a reaction to long term immersion in an environment that causes unbearable anxiety–not just one incident. Characters, to be real, are the product of all the things that have happened to them, the good and the bad. Some incidents leave more of an impression than others, but it’s the sum of our lives that shapes who we are.
Films, I’ll admit, are the worst. We are introduced to a character who is driven and obsessed, and then we see The Fateful Day That Changed His Life Forever in a flashback, and then at the finale he must overcome the memory of his trauma in order to save the day.
Novelists, however, sometimes do it, too. There is no excuse for it in a novel. We have the space to explore a character in detail, we can use internal monologue, multiple flashbacks, present the character’s life as a whole, not just a series of plot points.
Something to consider.