A little over a year ago, I landed wrong after hopping a fence and sprained my ankle badly. Although it doesn’t hurt anymore, it didn’t quite heal right, so my left ankle is much knobblier and more puffy than my right. This kind of thing happens to people all the time. We’ll get through some calamity – minor or major, physical or mental – without severe permanent damage, but we’ll be marked by it in some way for the rest of our lives.
Fiction writers will frequently create characters who have been shaped by a traumatic event in their pasts. These characters may have strange mannerisms or attitudes; they may be difficult to get along with; they may even show impulses that shock the reader at first viewing. It’s tempting to explain these quirks as soon as humanly possible, but giving into that temptation might not be a good idea.
When you have a main character with a troubled past, you have the opportunity to add a degree of suspense to your character development. The character’s behavior becomes a mystery that the audience wants to solve – but not too quickly. In real life, people carefully set boundaries about the parts of themselves that they see as the most vulnerable. The audience expects your characters to behave the same way, only letting their guard down and revealing the secret to the mystery when they’re talking with someone they trust completely.
Ideally, the moment when a characters’ old wounds are finally explained to the audience is dramatic and satisfying. The reader finally has an explanation for behavior that has mystified them throughout your story. To pull this off, however, you need to be sure to realistically portray your character keeping their guard up until the moment is ideal for an important revelation which has a significant effect on the plot.